Breaking changes:
- Node `(variable)` was renamed to `(expr_double_quotes)`.
- Node `(variable_raw)` was renamed to `(expr_single_quotes)`.
- Node `(string)` was renamed to `(str_double_quotes)`.
- Node `(raw_string)` was renamed to `(str_single_quotes)`.
- Node `(raw_string_quote)` was removed.