Hide watchers from api work package response if user not authorized
Hide watchers tab if user isn’t allowed to view watchers…


… currently the permission is derived from whether the API embeds watchers or not. If the user is allowed to view work packages the API response at least contains an empty array.
Accessible (tabbable) delete watcher link on details pane
Merge pull request #1642 from opf/fix/view-watch-list-permission
Merge pull request #1643 from opf/fix/accessible-watcher-delete-links

Accessible (tabbable) delete watcher link on details pane
Added endpoint for creating relations
Added endpoint for deleting relationships
Added authorization to creating and deleting relations