Fixes#10501
The problem was that didn't have access to the updated contact from status-go after banning or unbanning, so we just changed the banned property, but there is more that gets changed in the backend, like `removed` being set to `true` as well.
With this fix, when you unban someone, you go back to a fresh start, as **non** contact, so you need to send a request again. That was the state you got if you restarted the app, so "re-sync" the state with status-go.
Another issue was on the frontend (QML). When banned, and after restarting to get the right state, the unban button would be disabled and the Add contact request button would show, which is not good. We only want to send requests when unbanned.