[FEAT] Support RemoteFunctions

[sasial-dev]

Describe your feature

Events should be able to return a value

Alternatives

Creating two events (one for each way)

Implementation Details

Careful decision will have to be made as to if we use RemoteEvents under-the-hood and then create a mock remotefunction-like interface in zap (so we don't yield the thread!).

[jackdotink]

Thinking about syntax for this:

funct name = {
	call: SingleAsync, -- SingleAsync or SingleSync
	args: f64, -- Ty
	rets: boolean -- Ty
}

Functions cannot be called from the server, only the client - so we can omit the from field.
Functions can only have one listener, so we only allow Single listeners.
Functions have different argument and return types, we we have two fields for them.

We also need to consider how we're going to handle yielding. Currently Zap does not yield, and ideally we have an option to allow users to choose between yield, promise-evaera, promise-nevermore, promise-redblox, and future. There might be other promise implementations, and we could support those as needed.

[sasial-dev]

Supporting different promise implimentations feels like a pain!
We could have yield/promise/future - but other than that I believe it's not worth it.
After all - Promises should be using the same API...

[jackdotink]

that works, we can have a opt for the path to require promise impl from, and always use .new to construct them.

[sasial-dev]

And if futures use the same API - then you just pass it as a the path of promise?

[jackdotink]

Futures do not use the same API