[FR] use WGTunnel for Wireguard intent

[maurerle]

Is your feature request related to a problem? Please describe.
The official wireguard app is not supported on F-Droid anymore - see here https://android.stackexchange.com/a/254263.
WGTunnel https://github.com/zaneschepke/wgtunnel
is a great alternative, which uses different intents.

It is needed to start and stop wireguard once a day using easer, when having a DynDNS setup.

The WGTunnel intents are described in:
zaneschepke/wgtunnel#44 (comment)

Describe the solution you'd like
I'd like to have an additional wgtunnel intent shortcut to start and stop wireguard tunnels with this.

Describe alternatives you've considered [optional]
Otherwise one has to keep using the old wireguard android implementation, which was reomved from F-Droid and is not available as a FOSS app.
https://android.stackexchange.com/a/254263