Add code action to introduce _ in numeric literals

[crtschin]

Closes #4650

This ended up being a bigger change than I intended. Some notes:

• I followed the groupings in the linked issue per format.
• I removed the regex-based approach for matching formats for simple string-matching. I didn't quite see an easy way to reuse it, as underscores can appear in any position in a literal. Makes it so we get the "fixing" functionality for semi-free.
  • I did reuse the regex's in the tests.
• NumericUnderscores is another extension, now the code action can add multiple of these.

[fendor]

Thank you for contribution, this looks great to me!

Waiting for another review by @drsooch who is the maintainer of this plugin :)

[fendor]

No other reviews, so let's merge! Thank you for your contribution!

[mergify]

This pull request has been removed from the queue for the following reason: checks failed.

The merge conditions cannot be satisfied due to failing checks:

• ❌ test_post_job

You can check the last failing draft PR here: #4748.

You may have to fix your CI before adding the pull request to the queue again.
If you update this pull request, to fix the CI, it will automatically be requeued once the queue conditions match again.
If you think this was a flaky issue instead, you can requeue the pull request, without updating it, by posting a @mergifyio requeue comment.

[fendor]

Ok, this merge queue doesnt seem to work how I would expect it to :)