Remove the remove all dialog

[TheOneRing]

          I'd remove the dialog at all.
          if all files got deleted from the server, the default should be that all files get also deleted from the client. the server is the source of truth; files can be restored from the server trashbin if this was done unintentionally.

Originally posted by @tbsbdr in #11545 (comment)

Additionally, the functionality was limited nowadays, as with virtual files the local backup was only partly existing.

[saw-jan]

Tested on ownCloud 6.0.0.13631-daily20240405 [de909e]

No Remove All Files? dialog ✔️