Push notifications

[leto]

We need some kind of push notifications, to tell users they have new transactions/memos.

Android has many kinds!

https://developer.android.com/guide/topics/ui/notifiers/notifications

"Heads up" and "Lock screen" push notifications are the current plan.

[leto]

This has privacy implications. We should give our uses private defaults and let them tweak as needed.

For instance, push notifications could render zaddrs or memos or ztransactions as pop-up notifications even when a phone is locked, ruining most of the privacy if the phone were stolen. We must educate users about these risks when they enable Push Notifications.