* Revert "Revert "FEATURE: Publish read state on group messages. (#7989) [Undo revert] (#8024)""
This reverts commit 36425eb9f0.
* Fix: Show who read only if the attribute is enabled
* PERF: Precalculate the last post readed by a group member
* Use book-reader icon instear of far-eye
* FIX: update topic groups correctly
* DEV: Tidy up read indicator update on write
