Treat set up of MRP tunnels like other protocols

[postlund]

What to change?

Setting up the MRP-over-AirPlay tunnel is treated differently to protocols as it is will only generate an error log if something fails. This means you just end up with an error but pyatv will churn on as nothing has happened but with less functionality. It would be better if an exception is raised on connection error just so we know that it failed and can deal with it properly.

Adding a setting to disable tunnel set up would be good as well to handle problematic cases.