Reduce the scope of the CCW cache or consider lock free

[jeffschwMSFT]

In processes that heavy use of COM can have considerable contention on the CCW cache lock. Currently the lock is for the whole process (eg. per-appdomain).

[jkoritzinsky]

Looks like as part of dotnet/coreclr#20919 the CCW cache was changed to be per-LoaderAllocator instead of per-process.

[AaronRobinsonMSFT]

Confirmed @jkoritzinsky's observation. I am going to close this issue since the global lock has changed. We can revisit if we hear additional user feedback.

N.B. The new CCW management API will not suffer from this contention - see #32091.