Reset user context on account logout

[Supereg]

Description

The template app currently enforces to be logged into a user account. Once you log out from the account, a sheet pops up requiring you to sign back in, before you can continue to use the app.
While this works as expected, the Schedule is not paused. For example, the app continues to deliver notifications to complete the social support questionnaire.

Reproduction

1. Onboard the app.
2. Logout from your account.
3. Wait till 8am to get a schedule notification delivered.

Expected behavior

It would be expected that the app clears all currently queued scheduled notifications and only reschedule them once the user signs back in. This (probably) requires an additional API surface in SpeziScheduler module and some additional account related handling in the ScheduleView.

Additional context

No response

Code of Conduct

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