Allow Device to be Configured via MDM

[CoryFoy]

Is your feature request related to a problem? Please describe.
Agencies may deploy large number of devices via MDM solutions. Part of these deployments are configuring applications running on the devices

Describe the solution you'd like
Allow TAK Tracker to be configured via MDM including the server connection and app settings

[CoryFoy]

This came up from Discord - the two things we'll need to do here are

1. Ensure the server connection/identity can be configured via MDM. Since we store the identity for the server in the keychain we'll need some way of parsing the certs and storing that through MDM or on first run if configured

2. Allowing app preferences / settings to be configured via MDM such as showing the map, stale time, call sign, etc. It may be worth adding in whether certain options are available - such as the ability to see callsign or map options in the settings pane once they've been set