Change `topic_id` to polymorphic approach (In the next step we will allow assigning to individual post)
`topic_id` column is still used for efficient display of assigned users on topic list (to avoid scanning posts)
On the group assignment page, we should be able to display
- all topics assigned to that group + to user belonging to that group
- all topics assigned directly to group
- all topics assigned to individual user
Ability to assign groups.
To assign group, user must have a right to send a message to that group.
In addition, 2 jobs were introduced, - AssignNotification and UnassignNotification to inform interested users in the background about the new assignment.
Adds three new search modifiers:
- in:assigned for assigned topics
- in:unassigned for unassigned topics
- assigned:{username} to list topics assigned to a specific user
These modifiers are all made available in the advanced search sidebar
* FEATURE: Display PMs in assigned activity and differentiate them.
* FEATURE: Unassign/Re-assign tasks from the activity view
* Remove bulkAssign. Reuse assign/unassign with a service. Change PM icon position
* Reuse ListItemDefaults instead of duplicating code.
* Conditionally show/hide feature if list items defaults is present in core