Bug 38175: (follow-up) Refactor staff interface additions to vanilla JS; adjust modul...

Bug 38175: (follow-up) Refactor staff interface additions to vanilla JS; adjust modules, controllers for coding guidelines and consistency

In the spirit of the current movement for more modern JS, the refactor tries to limit jQuery usage.

Test plan:
    1) Create a booking on a bookable item
    2) Cancel it and see that it's simply deleted
    3) Apply the patch and run “restart_all”.
    4) Repeat the same cancel operation and see that it's still there, albeit with a different appearance.
    5) Try the filters in the table

Signed-off-by: Paul Derscheid <paul.derscheid@lmscloud.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>