Consolidate parsing of Expr::Name in TypeAliasName, MatchName, and Atom<Goal> #98

We have three parser descriptions for in the LALRPOP grammar for generating Expr::Name from an Identifier.

• TypeAliasName
• MatchName
• Atom<Goal>

These could be consolidated into a single reused identifier for simplicity and clarity.

Originally posted by @MichaReiser in #97 (comment)