[Local GC] Move operations on CLREventStatic to the EE interface (dotnet/coreclr...

[Local GC] Move operations on CLREventStatic to the EE interface (dotnet/coreclr#10813)

* [Local GC] Move operations on CLREventStatic to the EE and add their functionality to the interface

* Fix a missed case

* Split GetWaitForGCEvent into two smaller interface methods to avoid exposing the event itself on the interface

* Initial implementation for Unix

* Complete unix implementation

* Make it work on Windows

* Remove redudant methods from GCToEEInterface

* Fix the Linux build

* First part of code review feedback: make GCEvent dispatch statically (Windows)

* Second part of code review feedback: make GCEvent dispatch statically (Unix)

* Standardize implementation across Windows/Unix (apparently MSVC is more lenient about constructor names than clang)

* Address code review feedback: Add Create*Event methods back onto GCEvent and remove them from GCToOSInterface

* Address code review feedback: remove a dead define

* Remove a bad comment, remove an unnecessary friend class, fix some formatting issues

* Fix an issue when initializing a GCEvent on Linux (should not be allocating an Impl in the constructor)

* Fix the same issue on Windows (less bad, just leaks memory instead of asserting)

Commit migrated from https://github.com/dotnet/coreclr/commit/13812bfd0f6eda442c944f416e8c871b18d99e3f