ISPN-5150 In testing, near cache events should fire after event

[galderz]

• Before this fix, events were being fired before the near cache had been updated, and as a result of that, client code was making working on assumptions that might not have yet been applied in a multi threaded environment.
• Instead of using the Hot Rod async thread pool for client listeners, created a simple cached pool where each thread is associated with a client listener, and the thread name is adjusted when the client listener starts.
• Added multiple TRACE log messages to help debugging.

[tristantarrant]

Pushed, thanks