[Mono] Hot Reload: Add support for updating generic methods

[lambdageek]

Related CoreCLR issue #80749

Razor scenario:
dotnet/aspnetcore#46100

VS feedback:
https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems/edit/1714548

Related:
Issue #11036 tracks support for updating members of generic types in CoreCLR.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.