comments should be recognized in (almost) every context, keywords should be recognized inside expression contexts too

[filipw]

1. #comments added to type-parameter-list, parameter-list, parameter, udt-declaration, struct-field, import-export-directive, open-directive, tuple-pattern
2. #keywords added to #expression
3. end widened to (?=;|)|}) for local-declaration, array-assignment, local-assignment, quantum-declaration

Reverse-integrated based on microsoft/qdk#3508