Generated Code doesn't work with actor annotated dependencies

[vsanthanam]

@MainActor annotated dependencies, produce uncompilable code

To support all actor annotations, I think the solution here is to make the getters for those dependencies async,

to support just @MainActor, we could just require that dependency access happen on the main thread by Component, Dependency, and generated code with @MainActor

[vsanthanam]

Create a proof of concept PR #423