Handle disabling of users

[pauljohanneskraft]

Problem

We can now disable users that are, e.g., no longer part of the study by setting their disabled property in Firestore to true. Whenever that property is set (and the token has been refreshed, technically), the user won't be able to do anything anymore, except reading its own user information.

Solution

We should update our snapshot listener to check for that disabled property and if that is set to true, we replace the UI by a simple message with a message such as "You are no longer part of this study" - please have a look at the iOS app on how that is supposed to look.

Additional context

No response

Code of Conduct

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[PSchmiedmayer]

We should replicate the setup in StanfordBDHG/ENGAGE-HF-iOS#133