Trigger data refresh on app start

## What Happened

It seems like Tasks needs quite a while to pick up changes done in the backend. Therefore I suggest we trigger a data refresh on each app start Also it would be great to indicate this activity to the user by showing a spinner.

## Expected Behavior

Whenever the app is started, it should provide the user the latest information.

## Steps to Reproduce

1. Open the Tasks app and wait a bit
2. Close the Tasks app
3. Change a task in the backend
4. Re-Open the Tasks app

The task in question still shows the old values.