533. Fix race condition between onStartPartitionSession and onPartitionSessionClosed

[ekuvardin]

Connected to #553

AsyncReader.onStartPartitionSession can be called before AsyncReader.onPartitionSessionClosed due to race condition

By the way onStopPartitionSession managed by ydb core and after running some test examples couldn't find any races

I write two test
testEventOrderingGuarantees - guarantees in one reader
testSessionCloseRaceCondition - guarantees in two reader and simulate situation like in attached issues

[codecov-commenter]

Codecov Report

❌ Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 68.82%. Comparing base (597ebc0) to head (6246cba).

Files with missing lines	Patch %	Lines
...main/java/tech/ydb/topic/read/impl/ReaderImpl.java	88.88%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #605      +/-   ##
============================================
+ Coverage     68.65%   68.82%   +0.16%     
- Complexity     3096     3102       +6     
============================================
  Files           355      355              
  Lines         15305    15309       +4     
  Branches       1624     1626       +2     
============================================
+ Hits          10508    10536      +28     
+ Misses         4131     4102      -29     
- Partials        666      671       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.