openolat#233: show a disclaimer when choosing to create a course with learning path node access type

Show a warning in test, test part and sections if the number of max.
attempts is overwritten by under elements

- Move topic edit buttons to the list of topics
- Only one view to edit topic and organizers
- Organizer selection in a multi dropdown menu
- Help buttons to initial values

to have the advantages of both:
- Nice GUI of the selection view
- Table display of the edit view

backgrounds

And tests of the enrollment process, finally.

Implement CSRF protection in the page editor v2.0, enhance z-index and
opacity of edited element during dragging