ENG-6213 : Create long lived backup client

Start and stop the rust backup client handler from JS if a user is a logged in staff and enables it in the settings.

Depends on D10621

Monitor backup service logs and:

• Enable the backup handler in menu -> the websocket in connected
• Check that the websocket is disconnected after disabling the backup handler in menu or logging out
• Check that the websocket automatically reconnects after app is closed and opened (without logging out) and when backup service is killed (simulating network issues)