0.8.0

• Remove ID, TYPE, NOT op codes. Moving these back to builtins as it solves a lot of issues around directly referencing builtins like id
• Builtins now return ExprResult<Value> instead of Value
• Improved typechecking
  • Using builtins as call args
• As typing to AST
  • This happens in two passes. Once in the parser and once in the compiler.
• Changed BuiltinFn::func to be a function pointer versus accepting closures.
• Error diagnostics now have what type of error it was (e.g. lexical, compiler, runtime)
• Add Type::Type to help support first class type
• Update grammar to support Type identifiers