[fix](stream_load) Fix stream load IPv6 host parsing

[re20052]

What problem does this PR solve?

Problem Summary:

In LoadAction#splitHostAndPort, the endpoint string (e.g. backend's publicEndpoint / privateEndpoint, in host:port format) was split by : to get the host and port. This does not work for IPv6 addresses since IPv6
addresses themselves contain colons.

This PR uses Guava's HostAndPort.fromString to parse the endpoint string, which correctly handles both IPv4 and IPv6 formats.

Release note

Fix stream load redirect failure when backend endpoint is an IPv6 address.

Check List (For Author)

• Test

  • Regression test

• Behavior changed:

  • No.

• Does this need documentation?

  • No.

[hello-stephen]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[re20052]

run buildall

[re20052]

/review

[hello-stephen]

FE Regression Coverage Report

Increment line coverage 2.56% (1/39) 🎉
Increment coverage report
Complete coverage report

[hello-stephen]

TPC-H: Total hot run time: 28699 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpch-tools
Tpch sf100 test result on commit bf5a8276ac424adc8a0f18185703c852f2af4ec3, data reload: false

------ Round 1 ----------------------------------
orders	Doris	NULL	NULL	0	0	0	NULL	0	NULL	NULL	2023-12-26 18:27:23	2023-12-26 18:42:55	NULL	utf-8	NULL	NULL	
============================================
q1	17748	4019	3967	3967
q2	q3	10808	1360	783	783
q4	4686	470	345	345
q5	7566	898	609	609
q6	197	175	137	137
q7	820	861	625	625
q8	9992	1670	1597	1597
q9	6921	4518	4448	4448
q10	6786	1827	1512	1512
q11	441	271	250	250
q12	665	433	305	305
q13	18173	3382	2814	2814
q14	279	262	247	247
q15	q16	817	770	714	714
q17	1408	1105	700	700
q18	6751	5719	5446	5446
q19	1385	1195	1094	1094
q20	512	404	264	264
q21	5997	2806	2531	2531
q22	447	368	311	311
Total cold run time: 102399 ms
Total hot run time: 28699 ms

----- Round 2, with runtime_filter_mode=off -----
orders	Doris	NULL	NULL	150000000	42	6422171781	NULL	22778155	NULL	NULL	2023-12-26 18:27:23	2023-12-26 18:42:55	NULL	utf-8	NULL	NULL	
============================================
q1	4818	4737	4702	4702
q2	q3	4896	5265	4657	4657
q4	2096	2206	1373	1373
q5	4881	4881	4713	4713
q6	235	181	134	134
q7	1824	1749	1584	1584
q8	2371	1929	1927	1927
q9	7423	7459	7393	7393
q10	4775	4648	4187	4187
q11	571	379	350	350
q12	726	741	527	527
q13	3055	3358	2799	2799
q14	267	281	258	258
q15	q16	677	706	612	612
q17	1261	1257	1240	1240
q18	7347	6943	6887	6887
q19	1083	1101	1067	1067
q20	2213	2214	1937	1937
q21	5230	4548	4450	4450
q22	501	453	445	445
Total cold run time: 56250 ms
Total hot run time: 51242 ms

[hello-stephen]

TPC-DS: Total hot run time: 170252 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpcds-tools
TPC-DS sf100 test result on commit bf5a8276ac424adc8a0f18185703c852f2af4ec3, data reload: false

query5	4325	631	485	485
query6	435	204	190	190
query7	4824	580	314	314
query8	361	226	213	213
query9	8797	4050	4102	4050
query10	460	344	266	266
query11	5848	2359	2201	2201
query12	155	104	101	101
query13	1263	608	432	432
query14	6421	5438	5073	5073
query14_1	4441	4464	4413	4413
query15	208	198	178	178
query16	1014	454	446	446
query17	1137	725	594	594
query18	2725	499	360	360
query19	215	195	149	149
query20	112	111	109	109
query21	217	143	123	123
query22	13731	13667	13657	13657
query23	17406	16495	16242	16242
query23_1	16335	16416	16695	16416
query24	7535	1820	1307	1307
query24_1	1336	1325	1289	1289
query25	598	469	412	412
query26	1312	305	179	179
query27	2653	555	329	329
query28	4422	2036	2020	2020
query29	1119	634	513	513
query30	306	242	198	198
query31	1115	1070	956	956
query32	110	67	64	64
query33	546	333	307	307
query34	1156	1171	653	653
query35	758	775	680	680
query36	1374	1390	1176	1176
query37	152	107	92	92
query38	3239	3165	3085	3085
query39	936	921	893	893
query39_1	884	880	871	871
query40	216	123	100	100
query41	66	65	63	63
query42	99	95	92	92
query43	326	332	290	290
query44	
query45	198	185	182	182
query46	1068	1250	721	721
query47	2375	2386	2219	2219
query48	407	406	309	309
query49	630	480	367	367
query50	998	367	266	266
query51	4321	4277	4255	4255
query52	87	90	76	76
query53	238	269	192	192
query54	279	221	196	196
query55	80	75	70	70
query56	233	232	215	215
query57	1425	1389	1298	1298
query58	243	218	207	207
query59	1604	1667	1478	1478
query60	279	261	230	230
query61	162	159	153	153
query62	690	663	592	592
query63	239	189	183	183
query64	2509	795	658	658
query65	
query66	1719	455	345	345
query67	29662	29763	29558	29558
query68	
query69	425	303	268	268
query70	989	997	933	933
query71	297	233	218	218
query72	2947	2689	2325	2325
query73	811	789	442	442
query74	5127	4944	4788	4788
query75	2645	2589	2246	2246
query76	2340	1160	791	791
query77	359	373	295	295
query78	12410	12574	11891	11891
query79	1428	1080	780	780
query80	1303	482	414	414
query81	530	277	245	245
query82	612	156	122	122
query83	318	271	248	248
query84	261	140	107	107
query85	907	533	450	450
query86	436	295	291	291
query87	3468	3335	3197	3197
query88	3697	2773	2735	2735
query89	436	383	328	328
query90	1976	179	193	179
query91	176	172	137	137
query92	64	63	60	60
query93	1634	1466	957	957
query94	730	360	336	336
query95	671	465	354	354
query96	1017	791	377	377
query97	2731	2682	2564	2564
query98	215	206	209	206
query99	1187	1213	1064	1064
Total cold run time: 252592 ms
Total hot run time: 170252 ms

[liaoxin01]

LGTM

[liaoxin01]

/review

[github-actions]

PR approved by at least one committer and no changes requested.

[github-actions]

PR approved by anyone and no changes requested.

[github-actions]

Review opinion: no blocking issues found. The change is small and uses Guava HostAndPort to address the IPv6 parsing problem in stream-load redirect endpoint handling.

Critical checkpoint conclusions:

• Goal and proof: The implementation addresses colon-splitting failures for bracketed IPv6 host:port inputs. Existing tests do not directly prove the new IPv6 parsing behavior; adding focused LoadActionTest coverage for bracketed IPv6 Host headers and public/private endpoints would reduce regression risk.
• Scope and clarity: The modification is focused and minimal, limited to replacing ad-hoc parsing in LoadAction.
• Concurrency and lifecycle: No new shared state, locks, threads, static initialization dependency, or lifecycle-sensitive behavior was introduced.
• Configuration and compatibility: No new configuration or storage/protocol format change was introduced. Existing endpoint strings now need standard bracketed IPv6 host:port syntax, which is appropriate for disambiguating IPv6 ports.
• Parallel paths: The changed parsing is applied to both request Host parsing and backend public/private endpoint parsing in this redirect path. No separate equivalent parsing path was found in this PR.
• Error handling: Invalid endpoint formats are converted to LoadException/AnalysisException consistently with the surrounding code.
• Data correctness, transactions, persistence, and FE-BE variable passing: Not applicable to this HTTP redirect parsing change.
• Observability: Existing logs are sufficient for invalid header/endpoint diagnosis.
• Performance: No material performance concern; parsing happens per redirect request and avoids obvious hot-loop work.

User focus response: no additional user-provided review focus was specified.

Residual risk: IPv6 redirect URL construction appears safe because RestBaseController builds the URI from host/port components, but there is no direct test asserting the final redirect Location for IPv6 endpoints.