User Management: Permissions cannot be assigned for "all" available languages

[drfho]

Ref: https://github.com/idasm-unibe-ch/unibe-cms/issues/1289

For any access-rights the language has to be choosen explictly. If later languages are changed (in portal-root or some clients) the user-rights need to be fitted manually to the new situation. With hundred or editors this can get a lot of effort. So why not changing the UI from the tranditional allowance-orientation to a restriction-orientated view and add the explicitly named all-case (all languages are accessible).