Handle errors while a project is being deleted asynchronously.

What does this MR do?

1. Rescue all errors that Projects::DestroyService might throw, to prevent the worker from leaving things in an inconsistent state

2. Unmark the project as pending_delete

3. Add a delete_error text column to projects, and save the error message in there, to be shown to the project masters/owners.

Are there points in the code the reviewer needs to double check?

Are there any actions apart from the ones mentioned above that we might need to take when Projects::DestroyService errors out?

What are the relevant issue numbers?

Closes #29289 (closed)

Tasks

• Investigation
• Implementation
  • Errors don't bubble up
  • Unmark pending_delete
  • Don't do any of this if not async
  • Display error message on project homepage
• Tests
  • Added
  • Passing
• Meta
  • CHANGELOG entry created
  • API support added
  • Branch has no merge conflicts with master
  • Squashed related commits together
  • Added screenshots
  • Check for clean merge with EE
  • Documentation added/updated
• Review
  • Reviewer
  • Maintainer
• Wait for merge