pushToken enhancement

[galenriley]

Add endpoint to update push token-related info without incrementing counter

Modify schema and app to accommodate

.user: id of logged in user on this device (plus maybe email or something readable)
.settings: Object (future use, for notification filters and other stuff TBD)

[galenriley]

segment push messages by .expoExperience and send in batches
possibly add flag to push token documents to never push to a particular user to avoid unconfirmed expo developer app issue

[galenriley]

maybe related, grab notifications from the background
https://docs.expo.io/versions/latest/sdk/background-fetch/

[tacoman]

@galenriley old issue here, is it still relevant? I can't remember all the motivations involved.

[galenriley]

iirc, the server is double-counting checkins, and I forget the background notification fetch thing.