nixos/connman: add TODOs regarding connman + network-manager

nixos/modules/services/networking/connman.nix

···
       assertion = !config.networking.useDHCP;
       message = "You can not use services.connman with networking.useDHCP";
     }{
+      # TODO: connman seemingly can be used along network manager and
+      # connmanFull supports this - so this should be worked out somehow
       assertion = !config.networking.networkmanager.enable;
       message = "You can not use services.connman with networking.networkmanager";
     }];

pkgs/tools/networking/connman/default.nix

···
   connman = callPackage ./connman.nix { };
 
   connmanFull = callPackage ./connman.nix {
+    # TODO: Why is this in `connmanFull` and not the default build? See TODO in
+    # nixos/modules/services/networking/connman.nix (near the assertions)
     enableNetworkManager = true;
     enableHh2serialGps = true;
     enableL2tp = true;