Port users of `RawAst` to `Ast` ✨🚀

[kazcw]

Eliminate usage of RawAst types, so that the types can be eliminated. This will improve performance, as most users of RawAsts must create one from an Ast, which is quite expensive. It will also improve simplicity, as Ast is an easier-to-use replacement.

• Port CodeEditor to Ast
• Port alias analysis to Ast