Parse deploy / RPC arguments using IDL

[ennsharma]

What is the problem that you're trying to solve?
If deploy / RPC arguments are not passed in as the correct type (i.e. they're entered via CLI and so read as strings), deploys / RPCs fail. We need to parse these arguments.

Describe the solution you'd like
Currently, we have a WIP implementation for an IDL type that lets us specify the name and type of arguments. We should finish this implementation, and then use it to typecheck and parse arguments as necessary.