## Summary
This PR updates the logic for parsing type annotation to accept a
`ExprStringLiteral` node instead of the string value and the range.
The main motivation of this change is to simplify the implementation of
`parse_type_annotation` function with:
* Use the `opener_len` and `closer_len` from the string flags to get the
raw contents range instead of extracting it via
* `str::leading_quote(expression).unwrap().text_len()`
* `str::trailing_quote(expression).unwrap().text_len()`
* Avoid comparing the string content if we already know that it's
implicitly concatenated
## Test Plan
`cargo insta test`