Improve the performance of invoking events

[manodasanW]

• Reduced the # of allocations on the event invoke code path.
• Move the custom type mapping logic in FromABI to CreateObject which allows for better caching of both the RCW for the ptr and the factory function used to create the RCW.
• Removed the use of Action via MarshalDelegateInvoke in the event invoke code path on .NET 5.
• Moved to using ThreadStatic rather than ThreadLocal for the variable which stores the RCW type as it looks to be more performant according to benchmarks.
• Avoid boxing when checking if it is a reference to a managed object and also avoid the need to create a IObjectReference to do so.
• Reduce the # of IObjectReferences created by creating a specialized version of CreateCCW which gives you the ObjectReference with the right vftbl and does a QI.
• Added a set of benchmarks that helped evaluate the improvements

[Scottj1s]

thanks!