* GreenField: Notifications API
This refactors notifications so that we dont have a bunch of duplicated direct access to db contexts in controllers and then introduces new endpoints to fetch/toggle seen/remove notifications of the current user.
* add tests + docs
* fix test
* pr changes
* fix permission json
This allows plugins to create custom dbcontexts, which would be namespaced in the scheme with a prefix. Migrations are supported too and the table would be prefixed too
* Allow disabling notifications per user and disabling specific notifications per use
closes#1974
* Add disable notifs for all users
* fix term generator for notifications
* sow checkboxes instead of multiselect when js is enabled
* remove js dependency
* fix notif conditions
* Add No JS support for notification seen toggle
* Invalidate cache when user toggles seen/massaction
* mark notif as seen after click
* add additional mass actions
* fix formatting
* add pav changes
* invalidate cache on new notifs
