Notify users when their CI minutes quota has run out

What does this MR do?

TODO:

• Send email to Group owners when quota has run out.
• Send email to owner of personal namespace when quota has run out.
• Update In-app banner notification.
• Update docs.

Screenshots

Message sent to Owners

Message shown to Owners

Message shown to non Owners

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance and testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers

Closes #11629 (closed)