Add WireGuard support

[AsciiWolf]

Intel ConnMan now supports WireGuard protocol. It would be great if this support could also be added to cmst.

[progandy]

I don't see anything that cmst has to do for basic support. I guess it would be nice to have a menu for wireguard settings in the vpn editor, and maybe an import option for wg-quick configuration files.

[andrew-bibb]

There are a handful of configuration options that have been added. I will be adding these to the VPN provisioning editor.

ConnMan is doing a release soon (first in about a year) so I'm going to be bringing CMST up to date with that.

[andrew-bibb]

VPN provisioning editor code for WireGuard is done and uploaded here. While it is included it will not be visible to a user unless they are running Connman version 1.38 or higher.