Introduction of a new device class (teacherlaptop).

- Wifi-devices will be managed by NetworkManager
 - (USB-)Dockingstation with same MAC as internal device
   will be assigned to virbr1
 - users with role-teacher have privilege
   - to create new NetworkManager connections
   - install additional software
   - change luks-key
 - package plasma-discover will not be removed (for teacherlaptops)
 - http-proxy-Settings will be configured by auto-detect
 - providing sudo-script to mount default-school from server after
   wireguard-connection is established

roles/lmn_teacherlaptop/files/lmn-networkmanager.rules

@@ -0,0 +1,6 @@
+polkit.addRule(function(action, subject) {
+    if (action.id == "org.freedesktop.NetworkManager.settings.modify.system" &&
+        subject.isInGroup("role-teacher")) {
+            return polkit.Result.YES;
+    }
+});