Support Sit(X) logins

[CoryFoy]

Is your feature request related to a problem? Please describe.
Users of PAR Government's Sit(X) TAK Server use OAuth for connections. So if they want to use TAK Tracker right now they have to set up a TLS certificate rather than the normal auth

Describe the solution you'd like
Support the Sit(X) OAuth flow for logging in

[CoryFoy]

Additional Notes:

• Make sure that the "Server Information" block shows the right thing when connected to a Sit(X) server (as well as when not connected to any server
• When unable to connect, make sure we don't clear out all of the connection information so we can try again later (specifically make sure we can come back into the app)
• Modify the Add Connection flow to close out the flow and Settings Screen when successfully connected (regardless of the method connection)