* Add column last_fetched_at to MyChannel & Thread tables and the migration
* Fix schema tests
* Handle lastFetchAt, retrieve threads on init and properly observe thread unreads (#6436)
* [Gekidou] Set lastFetchAt when fetching posts for a channel (#6437)
* Set lastFetchAt when fetching posts for a channel
* When resetting _preparedState set always to null
* Revert changes in WS
* Handle and set lastFetchedAt for MyChannel in iOS push notification
* feedback review
* iOS fallback to last post createAt if no lastFetchAt set
* Handle lastFetchAt on Android push notifications
* create storePostsForChannel local action
* Fix iOS fallback to last post create_at
Co-authored-by: Daniel Espino García <larkox@gmail.com>