Pipe: Fix concurrent TsFile reference increases

[Caideyipi]

Description

PipeTsFileResourceManager.increaseFileReference checked whether a resource existed before entering the creation critical section. Historical and realtime extractors could both observe a missing resource, then create and put separate PipeTsFileResource instances for the same hardlink. The later put overwrote the first reference count, so releasing one event could delete a hardlink that another event still needed and stop the pipe with FileNotFoundException.

This change rechecks the resource map after acquiring the segment lock. If another caller has already created the resource, it increments and reuses that resource instead of overwriting it.

A concurrent regression test starts 64 retain operations together and verifies that both the pipe-private and shared reference counts reach 64, then verifies complete cleanup after all releases. Before the fix, the test reproduced a lost count (expected: 64, actual: 58); with the fix, the full test class passes.

Validation:

• mvn -pl iotdb-core/datanode -Ddevelocity.off=true -Dtest=PipeTsFileResourceManagerTest test
• mvn -pl iotdb-core/datanode -Ddevelocity.off=true spotless:check
• mvn -pl iotdb-core/datanode -Ddevelocity.off=true checkstyle:check
• git diff --check

This PR has:

• been self-reviewed.
  • concurrent write
• added comments explaining the why and the intent of the code wherever it would not be obvious.
• added unit tests to cover the concurrent code path.

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Key changed/added classes

• PipeTsFileResourceManager
• PipeTsFileResourceManagerTest