Extend auto-triage/mention feature to failing builds in e.g. quickstarts

Right now when one make a change to Quarkus, they may inadvertently break the Quickstarts. It's generally easy to solve, but hard to spot, because it's hard to get properly notified about these failures.

For example I mainly work on Hibernate extensions on Quarkus. If I wanted to get notified when Hibernate quickstart builds start failing, my only option would be to subscribe to this issue, and then I'll be notified for every single quickstart failure, including those for the (many) extensions unrelated to Hibernate.

Solution proposal

In the bot, we already have code that:

• in some place, analyzes a build (in particular test failures) and reports problems, grouped by module.
• in another place, analyzes which directories a PR changed, then applies labels to that PRs and notifies the relevant people.

We could imagine that, on Quickstart build failures, the Quarkus bot, or an action, would analyze the build result, group propblems them by quickstart or relevant extension, then would provide a detailed report on the dedicated issue, and @mention the people responsible for these quickstarts or the relevant extensions.

Start by locating the bot or action paths that analyze build and test failures, group problems by module, and inspect changed directories for labels and mentions. Trace how Quickstart failures are reported to dedicated issue #6588; done means failures are grouped by quickstart or relevant extension and the responsible people are mentioned with a detailed report.