* remove useless slide management buttons. This commit removes the frontend
edit/publish/unlink buttons on slide cards (for the 'document' channel view)
as they were not handled on the backend side.
* hide slide type filter for documentation channels. The slide type filter
(including statistics) on the left side of the channel frontend view
was only handled for channels of type 'documentation'. This commit hides
the slide type stats/filters if the channel is not of type documentation.
* display add content/section buttons based on user rights. Fixes two channel
frontend issues with user rights management:
* Users that have the right to upload (can_upload field) should have the
"Add content" button available.
* The "Add section" button should only be available to website_publisher
accordingly to ACLs
Commit linked to task ID 1941250 and PR #31279.