Improve commit message drafting

The MR so far addresses:
- Use no reply email
- Parse issue ID (it was there but needed to use a different attribute)
- Trim space
- Message only (having message only and git command seem too repetitive, and a big use of space on issues with many contributors)

Not addressed:
- Editing the message: if the goal is for them to paste that into the merge UI, they should be able to edit it there I guess.
- Conventional commits select vs input text: I first thought of dropdown, but yeah, it's pretty flexible, so I kept it as text input.

This is merged now.

The email format used is: $email = $contributor_user->getAccountName() . '@' . $contributor_user->id() . '.no-reply.drupal.org';
This avoids extra calls to the GitLab api to use alternative emails.

Not addressed (from previous comment):
- Editing the message: if the goal is for them to paste that into the merge UI, they should be able to edit it there I guess.
- Conventional commits select vs input text: I first thought of dropdown, but yeah, it's pretty flexible, so I kept it as text input.

I will mark it as fixed, but if we need to iterate on it or redefine things we can reopen or open a follow-up issue.

Thanks, these are all great improvements!

Instead of reopening, I spawned a follow-up: ✨ Add a UI to change footer "token" values for each user Active

Automatically closed - issue fixed for 2 weeks with no activity.