It is not possible to display/generate receiving addresses without an Internet connection

[micressor]

Steps to reproduce:

1. Set phone into flight mode / shutdown network interface
2. Try to get a receiving addresses

The app hangs when trying to connect to the Electrum server.

It should be possible to display receiving addresses from the private key even in a place where there is no Internet.

version: 4.31.1

[benma]

The app only shows unused addresses. To be able to determine which addresses are unused, an internet connection is needed to scan the addresses.

To make this work, more things would need to work offline, e.g. show the account/balance with a note that it might be out of date (offline), etc. I am not sure we want to go this way with the app.

Fyi, you can get addresses offline using other wallet tools such as Electrum (on desktop only, not on mobile).

cc @jadzeidan