Cannot get name of generics in declaration

[JSAbrahams]

Description of Bug

Currently, no mechanism yet to get generics of declarations.

How to Reproduce

A small example:

class MyClass[T]
    def f(x: T) -> T => x

def x := MyClass[Int]()

Gives an error when trying to process the following in check stage:

def x := MyClass[Int]()

During the generate stage, it correctly identifies this as a function call.
However, the function name is a StringName, and this causes a problem because we call (pseudocode ahead) StringName::try_from(MyClass[Int]).
Because StringName does not know how to deal with Node:Index (which is how it is parsed).

Expected behavior

Should be converted to a StringName.
This should be a quick fix in TryFrom<&AST> for StringName.

Once implemented, then the internal generic logic of check stage which we implemented recently (in part to get collections to work) should take over.