Fix a crash where workers, in some conditions, should show a notification. These are sent to a dedicated channel with no importance.
Convert NotificationWorker to a CoroutineWorker and remove its use of `runBlocking`.
Fixes#3754
- Extend what was `NotificationWorkerFactory` to `WorkerFactory`. This
can construct arbitrary Workers as long as they provide their own
Factory for construction.
The per-Worker factory contains any injected components just for that
worker type, keeping `WorkerFactory` clean.
- Move `NotificationWorkerFactory` to the new model.
- Implement `PruneCacheWorker`, and remove the code from
`CachedTimelineViewModel`.
- Create the periodic worker in `TuskyApplication`, ensuring that the
database is only pruned when the device is idle.
Nik Clayton