Incorperate AnnouncementCenter for posts

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Feature request

Which Nextcloud Version are you currently using: (see administration page)
32

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
I would like a fork/alteration of the announcementCenter app for Teams.
A missing cornerstone for collaboration is group information through posts.
Talk is crowded with groups/chats and gets messy very fast. Important posts are easily missed if the user doesn't check all groups with unread posts often.

With an alteration of AnnoucementCenter from groups to teams one can post important posts to a team and this will be displayed in a widget on the dashboard.
The user Always sees new team messages when he loads the dashboard.

Describe alternatives you've considered
AnnoucementCenter is only maintained with limited effort. It's not likely they will implement this.

Additional context
Link to announcement center repo: https://github.com/nextcloud/announcementcenter/

The issue names no files, tests, or entry points. Start by reviewing the linked AnnouncementCenter repository and how circles currently expose team or group data; define the dashboard widget and team-post behavior, then verify the feature against those requirements.