[QA] moving shared folders into external storages behaves weird

[jnweiger]

Seen in 10.10.0 RC2

This is a followup of #39550 - where the share reciever tried to move the share. (That is fixed now) Now Let's try with the share owner:

• Both user admin and user01 have the SFTP external storage.
• That storage is configured without sharing permission.
• user Admin shares his toplevel folder Documents with user01
• user admin moves Documents into SFTP.
  • new Web UI Error message when share owner tries move into SFTP mount: "Failed to move Documents". BAD
  • classic UI Error message when share owner tries move into SFTP mount: "Could not move "Documents": You are not allowed to share /admin/files/SFTP/Documents" BAD.
• The folder is actually moved into the SFTP mount and it is still shared. (Although Sharing was not allowed in the SFTP mount. Ouch)