Better handling of Dependabot PRs

[gsmet]

Dependabot PRs are practical but... you end up with quite some work to get it included in our usual workflow:

• create a JIRA issue
• adjust PR title and description to reference the issue
• adjust the commits to include the issue number
• attach the PR to the issue

I wonder if we could automate at least some of these things. Maybe not for every Dependabot PR coming as we ignore some of them but if we could add a comment like:

@hibernate-bot jira

and get things done, that would be awesome.

Note that Quarkus GitHub App now comes with a new extension to handle commands so this part would be easy. The rest might me more complicated :).

Note: I don't think closing the issue automatically is a good idea as we usually deal with fixed versions.