Improve actor method invocation performance and flexibility

ASP.NET Core uses a type called [ObjectMethodExecutor](https://github.com/aspnet/AspNetCore/tree/dbba49cc256ef2ac0d4cc94cfd0e256d70dfea46/src/Shared/ObjectMethodExecutor) to generate efficient code for calling methods that take any arguments and return any result (async or not). It's pretty hardened and should be used instead of the raw method info to dispatch to actor methods.

cc @amanbha