Use ServerT with polymorphic monad

[ilyakooo0]

Ideally, I think we could just use types instead of a full server, but this is a what I could quickly do.

[ilyakooo0]

So, I made the server fuzz not require a server value, just the type of the server. The same can probably be done with the client side.

Although, it's not clear to me what the division between server and client is.

[ilyakooo0]

This doesn't work on my production API though. It fails with a type mismatch error. Do with this what you will. (:

Feel free to close this PR.