Separate @ mentions in notifications

Never miss a tag again. We've added a notifications tab for all "@ Mentions" that will help users find their most important notifications faster.

With this new tab, all @ mentions (group and direct) will go to the Mentions tab instead of Notifications. Like the other notification tabs, you'll be able to:

• Archive or mark as read
• Mark all as read
• Archive all

Thank you to April at Hiebing for this request!