optimize tidy check on src/tools/tidy/src/issues.txt

This change applies to the following:

- Handles `is_sorted` in the first iteration without needing a second.
- Fixes line sorting on `--bless`.
- Reads `issues.txt` as str rather than making it part of the source code.

Signed-off-by: onur-ozkan <work@onurozkan.dev>

Author: onur-ozkan