* Change admin announcement edition interface to use datetime-local
* Dynamically set announcement stop date as required if start date is set, set minimum date for stop date
* Change `all_day` to not be bound to presence of time-range
* Add pattern and placeholder as minimal fallback for browsers not supporting datetime-local
* Display datetime-local inputs as local time
Co-authored-by: Eugen Rochko <eugen@zeonfederated.com>
* Add announcements
Fix#11006
* Add reactions to announcements
* Add admin UI for announcements
* Add unit tests
* Fix issues
- Add `with_dismissed` param to announcements API
- Fix end date not being formatted when time range is given
- Fix announcement delete causing reactions to send streaming updates
- Fix announcements container growing too wide and mascot too small
- Fix `all_day` being settable when no time range is given
- Change text "Update" to "Announcement"
* Fix scheduler unpublishing announcements before they are due
* Fix filter params not being passed to announcements filter
