Rewrite `inline` attribute parser to use new infrastructure and improve diagnostics for all parsed attributes r? `@oli-obk` This PR: - creates a new parser for inline attributes - creates consistent error messages and error codes between attribute parsers; inline and others - as such changes a few error messages for other attributes to be (in my eyes) much more consistent - tests ast-lowering lints introduced by rust-lang/rust#138164 since this is now useful for the first time - Coalesce some useless error codes Builds on top of rust-lang/rust#138164 Closes rust-lang/rust#137950