lint_asn1: detect missing errors
Display a "missing error" error if a lint_exception exists in asn_config.json but isn't generated by the tool. Remove non-existent "tag missing" errors in r18 and r19 that were fixed with CR0573.
Display a "missing error" error if a lint_exception exists in asn_config.json but isn't generated by the tool. Remove non-existent "tag missing" errors in r18 and r19 that were fixed with CR0573.