better cleanup of user files on user deletion

[icewind1991]

Fix #9690

Handle cleanup of user data in the storage, not only the local fs.

Fixes user files not being deleted when using s3 primary storage.

to test:

• setup instance with s3
• create userA
• as userA upload some files
• delete userA
• create a new userA
• login as userA

On current master the files previously uploaded will be shown again, surviving the user delete.

[blizzz]

looks good – much better than before. did not test.

[kesselb]

fyi @pierreozoux @acsfer

[solracsf]

The problem i was having was not on user deletion, but on files deletion.
Use case at #20333 (comment)

Similar issues #26014 #24957

Does this PR helps in these cases?

[blizzz]

Should not this get backported, @icewind1991?

[pierreozoux]

It would be nice if it is backported :) But I also understand if it is not :)

Thanks for fixing it, it is nice for the environment and user's privacy!

[blizzz]

/backport to stable21

[metheos]

My local storage is no longer getting cleaned up since this was merged ☹
I manually put the removed lines from /lib/private/User/User.php back into my instance since I had a bunch of users to delete yesterday and didn't want to manually clear the storage and _storages and _filecache tables for all of them.

Nextcloud 22.1.1
Ubuntu 20.04.2
Apache 2.4.41
PHP 7.4.3

[blizzz]

@metheos please open a new issue with the requested details (especially log from the delete action)