[Feature Request] Wifi automatic cycle between AP-Client mode

[8f6e58ee]

If wifi is connected to an AP it should remain like that but if not connected it should cycle between 'Rumble' open AP and client mode for short intervals (maybe a random time between 1-2 minutes) to maximize chances to link to another Rumble peer and exchange a batch of messages. When in client mode, the handset should connect automatically to any 'Rumble' wifi which is open.

When turning to AP mode, disable 3G/4G data temporally to prevent abuse but allow the exchange of messages. Cutting internet access for short time shouldn’t affect other messaging apps too much. A small random time variation prevents two devices from being accidentally synchronized a never connecting to each other.

If possible, when leaving AP mode restore previous AP configuration (Wifi hotspot name and encryption/password)