Delete messages from device_inbox table when deleting device

[dklimpel]

Fixes: #9346
Replaces: #10098

Related:

• to_device messages aimed at a local device are not removed after that device is deleted #9346
• Synapse accepts to_device messages to hidden devices #9348
• Stop synapse from saving messages in device_inbox for hidden devices. #10097
• Streams tables are never cleared out #5888
• device_inbox never gets emptied #3599

Pull Request Checklist

• Pull request is based on the develop branch
• Pull request includes a changelog file. The entry should:
  • Be a short description of your change which makes sense to users. "Fixed a bug that prevented receiving messages from other servers." instead of "Moved X method from EventStore to EventWorkerStore.".
  • Use markdown where necessary, mostly for code blocks.
  • End with either a period (.) or an exclamation mark (!).
  • Start with a capital letter.
• Pull request includes a sign off
• Code style is correct (run the linters)

Signed-off-by: Dirk Klimpel dirk@klimpel.org