Location preference for nodes

[awlx]

It would be cool to define a preferred location like "MUC" or "Vienna" in our case as a node owner. And as long as there is still a reasonable balance between the two sites your node connects to the preferred location.

[T0biii]

just some brainstorming:

we can add here: https://github.com/freifunk-gluon/community-packages/tree/master/ffmuc-mesh-vpn-wireguard-vxlan a UCI value for the request and add maybe a toggle in the GUI
something like automatic, prefer MUC, prefer Vienna

the list of location should be in the firmware or retrieved via WGKEX wgkex.url/locations and autofresh every restart, x minutes