Delete orphaned media in clean command

[mbardelmeijer]

The use-case here is to automatically delete orphaned media objects, which also deletes them from the disk.

In database structure, it's common to use cascading deletes via foreign keys. When deleting database records like that, the Media object isn't automatically deleted due to its morphed relation. This delete action should be implemented by the developer to delete the related media objects in the deleting event, but this can be easily missed. No direct effects are visible on application level, but deleted storage objects remain indefinitely in the medias table, as well as on storage, which might infringe on GDPR requirements, as well as unnessesary storage used.

This PR adds logic to automatically delete orphaned models in the clean command. I've added it as an opt-out, but if a safer opt-in option (--delete-orphaned instead of --skip-orphaned) I've added it as an opt-in option, where --delete-orphaned needs to be included to delete orphaned models.

Happy to chat about other approaches if preferred :)

[freekmurze]

Could you add a test for this?

[freekmurze]

Could you also rebase with main. That should make the tests pass.

[mbardelmeijer]

The tests have been added. I've changed it to an opt-in function to ensure in complex cases we aren't deleting media objects where not wanted (i.e. complex global scopes, etc).

[freekmurze]

Thanks!