Prevent Virtual Thread Deadlocks by Replacing Synchronized Blocks

[Eistern]

This PR replaces synchronized blocks in the YDB SDK with ReentrantLock implementations to resolve deadlocks that occur when using AsyncReader with Java 23 virtual threads. Synchronized blocks inadvertently pin virtual threads to carrier threads, leading to thread starvation in high-concurrency scenarios.

This change unblocks adoption of virtual threads in YDB applications while maintaining backward compatibility.

Example stacktrace of the pinned virtual thread

#329476554 "reader-session-8/f998jjgudtv9jk4kf359-executor-worker-33912448" virtual
      java.base/jdk.internal.misc.Unsafe.park(Native Method)
      java.base/java.lang.VirtualThread.parkOnCarrierThread(VirtualThread.java:680)
      java.base/java.lang.VirtualThread.park(VirtualThread.java:612)
      java.base/java.lang.System$2.parkVirtualThread(System.java:2735)
      java.base/jdk.internal.misc.VirtualThreads.park(VirtualThreads.java:54)
      java.base/java.util.concurrent.locks.LockSupport.park(LockSupport.java:219)
      java.base/java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:754)
      java.base/java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:990)
      java.base/java.util.concurrent.locks.ReentrantLock$Sync.lock(ReentrantLock.java:154)
      java.base/java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:323)
      io.netty.buffer.PoolSubpage.lock(PoolSubpage.java:294)
      io.netty.buffer.PoolArena.tcacheAllocateSmall(PoolArena.java:160)
      io.netty.buffer.PoolArena.allocate(PoolArena.java:135)
      io.netty.buffer.PoolArena.allocate(PoolArena.java:127)
      io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:403)
      io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:188)
      io.netty.buffer.AbstractByteBufAllocator.buffer(AbstractByteBufAllocator.java:124)
      io.grpc.netty.NettyWritableBufferAllocator.allocate(NettyWritableBufferAllocator.java:51)
      io.grpc.internal.MessageFramer.writeKnownLengthUncompressed(MessageFramer.java:226)
      io.grpc.internal.MessageFramer.writeUncompressed(MessageFramer.java:172)
      io.grpc.internal.MessageFramer.writePayload(MessageFramer.java:143)
      io.grpc.internal.AbstractStream.writeMessage(AbstractStream.java:66)
      io.grpc.internal.ForwardingClientStream.writeMessage(ForwardingClientStream.java:37)
      io.grpc.internal.RetriableStream.sendMessage(RetriableStream.java:575)
      io.grpc.internal.ClientCallImpl.sendMessageInternal(ClientCallImpl.java:522)
      io.grpc.internal.ClientCallImpl.sendMessage(ClientCallImpl.java:510)
      io.grpc.ForwardingClientCall.sendMessage(ForwardingClientCall.java:37)
      io.grpc.ForwardingClientCall.sendMessage(ForwardingClientCall.java:37)
      [...]
      io.grpc.ForwardingClientCall.sendMessage(ForwardingClientCall.java:37)
      tech.ydb.core.impl.call.ReadWriteStreamCall.sendNext(ReadWriteStreamCall.java:95) // the thread is pinned here
      tech.ydb.topic.impl.SessionBase.send(SessionBase.java:80)
      tech.ydb.topic.read.impl.ReaderImpl$ReadSessionImpl.sendReadRequest(ReaderImpl.java:269)
      tech.ydb.topic.read.impl.ReaderImpl$ReadSessionImpl.lambda$onReadResponse$6(ReaderImpl.java:472)
      [...]
      tech.ydb.topic.read.impl.Batch.complete(Batch.java:32)
      tech.ydb.topic.read.impl.PartitionSessionImpl.lambda$sendDataToReadersIfNeeded$7(PartitionSessionImpl.java:337)
      [...]
      java.base/java.util.concurrent.ThreadPerTaskExecutor$TaskRunner.run(ThreadPerTaskExecutor.java:314)
      java.base/java.lang.VirtualThread.run(VirtualThread.java:329)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 20.68966% with 46 lines in your changes missing coverage. Please review.

Project coverage is 58.79%. Comparing base (291f913) to head (19ce14a).

Files with missing lines	Patch %	Lines
...a/tech/ydb/core/impl/call/ReadWriteStreamCall.java	0.00%	22 Missing ⚠️
...n/java/tech/ydb/core/impl/call/ReadStreamCall.java	0.00%	20 Missing ⚠️
...h/ydb/test/integration/docker/GrpcProxyServer.java	75.00%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #381      +/-   ##
============================================
+ Coverage     58.74%   58.79%   +0.04%     
- Complexity     2166     2167       +1     
============================================
  Files           320      320              
  Lines         12894    12900       +6     
  Branches       1265     1265              
============================================
+ Hits           7575     7584       +9     
+ Misses         4708     4705       -3     
  Partials        611      611              

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