Fix RPC handshake and connection stability

[achobanov]

Notes

RpcConnection is problematic. Potential causes:

• lack of internet on local network - I think mobile devices prioritize the network that has access to WWW.
• SignalR connection hands, then needs physical re-connect to re-establish transport and sginalr connections.
• investigate handshake and connection when using mobile data and no internet over wifi
• transport disconnects Witness manages to establish new connection. Why does it need phisical reconnect? Probably transport cuta off without notifying SignalR?

• Suggestions

• [x] Check IsConnected before trying to connect
• [x] Refactor indications for clarity - 2 separate spinners for handshaking and connection
• [x] Add Manual reconnect button
• [x] Handle OnDisconnected, OnReconnecting, OnReconnected with notitifications, deploy and investigate thoroughly on both Android and iOS

[achobanov]

Work was done in 1.2, but this spills over as there are connectivity issues still.