fix: .. the parser

[FauxFaux]

The new parser has broken ./generate_modules.sh in a number of places.

As a first ... pass, fix the parser to actually error on rejections, then fix all of the .proto files the parser just rejects, due to omissions or bugs.

• single-line comment parser was accepting no comments, because not doesn't seem to work like that
• missed whitespace handling for } in e.g. message.
• enums with multiple lines of comments between items
• enums with trailing semis