#1306 add test that reproduces the flaky problem with CopyOnWriteMap

[asolntsev]

it's a simplified version of what happens with FakeValuesService.MAP_OF_METHOD_AND_COERCED_ARGS.

@snuyanzin Can you help with fixing CopyOnWriteMap?

[what-the-diff[bot]]

PR Summary

• New Test Class Added A new test class named CopyOnWriteMapTest.java has been added. The primary function of this class is to thoroughly check and determine the performance and reliability of multi-threaded, simultaneous data access in a specific object class called CopyOnWriteMap.

• Introduction of concurrentPutAndGet() Method This method is a part of the new test class. It is specifically designed to carry out 'put' and 'get' actions on the CopyOnWriteMap object in a concurrent environment. Put simply, it tests if multiple threads can simultaneously and safely access and modify the data within this object type.

The overall goal of these changes is to ensure that our CopyOnWriteMap operates robustly and correctly under situations where multiple processes try to access and alter data at once.