Use consistent formatting for user-facing formatter errors (#6925)
## Summary
This PR changes the alpha formatter CLI to use the same format for
errors as the linter, e.g.:
<img width="868" alt="Screen Shot 2023-08-27 at 4 03 30 PM"
src="https://github.com/astral-sh/ruff/assets/1309177/9f3dea37-593b-4788-a0c0-e64bcf0d0560">
