[ISSUE #9738] Enable macOS tests and release store resources

[yym108]

Which Issue(s) This PR Fixes

• Fixes [Enhancement] Remove macOS platform skip logic from test cases to improve cross-platform compatibility #9738

Brief Description

Remove macOS-specific assumptions and early returns from 27 test classes across authentication, broker, store and proxy modules so their assertions execute on macOS. Isolate store fixtures and release their managers, stores, statistics services and temporary files to support actual execution.

Running the RocksDB transfer tests also exposed a flush executor that outlived MessageRocksDBStorage.shutdown(). Create the executor after the database opens, stop it before closing the database, and recreate it when the storage is reopened. Add a regression test covering executor termination, repeated shutdown, reopening and checkpoint preservation.

How Did You Test This Change?

• Executed the 27 affected test classes on macOS ARM64 with Zulu JDK 21: 273 tests passed, with 4 existing JUnit ignore records. These are the class-level ignores for DLedgerCommitlogTest, DLedgerMultiPathTest and AutoSwitchHATest, plus MixCommitlogTest.testFallBehindCQ.
• After the resource lifecycle changes, reran MessageRocksDBStorageTest and RocksdbTransferOffsetAndCqTest: all 9 tests passed with no skips.
• Ran the two transfer tests twice in the same JVM: live threads returned to the baseline of 6 after each round, file descriptors stayed at 144 after class loading, and no checkpoint files were left behind. The process exited naturally.
• Maven's configured Checkstyle/SpotBugs checks and git diff --check passed. Local JDK 21 execution used JaCoCo 0.8.12, Javassist 3.30.2-GA, Byte Buddy experimental support and JDK module opens, without POM changes.
• The complete repository suite and Windows/Linux execution were not run locally.