[ALICE3] Add preselections and histogram to alice3 cascade finding

[jesgum]

No description provided.

[github-actions]

O2 linter results: ❌ 5 errors, ⚠️ 0 warnings, 🔕 0 disabled

[alibuild]

Auto-approving on behalf of @jesgum.

[alibuild]

Error while checking build/O2Physics/code-check for 4df05c7 at 2026-07-08 20:42:

## sw/BUILD/O2Physics-latest/log
2026-07-08T20:29:45.118+0200 [23:140160811093632] [buildboxcommon_grpcretrier.cpp:177] [ERROR] Retry limit (0) exceeded for "ActionCache.GetActionResult()", last gRPC error was [14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8980: Failed to connect to remote host: Connection refused]
2026-07-08T20:29:45.119+0200 [23:140160811093632] [executioncontext.cpp:544] [ERROR] Error while querying action cache at "http://localhost:8980": 14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8980: Failed to connect to remote host: Connection refused
2026-07-08T20:31:15.225+0200 [23:140160811093632] [buildboxcommon_grpcretrier.cpp:177] [ERROR] Retry limit (0) exceeded for "FindMissingBlobs()", last gRPC error was [14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8980: Failed to connect to remote host: Connection refused]


## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 2 errors and 3 warnings.'
Found 2 errors and 3 warnings.
++ [[ 2 -gt 0 ]]
++ cat /sw/BUILD/38219eb2d58344587bef6c41f78e1cd23f525daf/O2Physics-code-check/errors.txt
ALICE3/TableProducer/alice3strangenessFinder.cxx:72:8: error: constructor does not initialize these fields: pdgDB [cppcoreguidelines-pro-type-member-init,-warnings-as-errors]
ALICE3/TableProducer/alice3strangenessFinder.cxx:420:7: error: do not use 'else' after 'return' [readability-else-after-return,-warnings-as-errors]
++ [[ 3 -gt 0 ]]
++ cat /sw/BUILD/38219eb2d58344587bef6c41f78e1cd23f525daf/O2Physics-code-check/warnings.txt
ALICE3/TableProducer/alice3strangenessFinder.cxx:686:35: warning: statement should be inside braces [readability-braces-around-statements]
ALICE3/TableProducer/alice3strangenessFinder.cxx:688:42: warning: statement should be inside braces [readability-braces-around-statements]
ALICE3/TableProducer/alice3strangenessFinder.cxx:701:80: warning: statement should be inside braces [readability-braces-around-statements]
++ [[ 2 -gt 0 ]]
++ exit 1
--

Full log here.

[vkucera]

@jesgum Please fix the issues.