nixos/systemd/networkd: add Varlink APIs

This adds:

- /run/systemd/resolve.hook/io.systemd.Network (DNS hook)
- /run/systemd/report/io.systemd.Network (metrics)
- /run/systemd/netif/io.systemd.Network (management)

Change-Id: I3d63b0723ae5f8f9496418d8f5d857809302155e
Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

nixos/modules/system/boot/networkd.nix

@@ -4231,8 +4231,10 @@ let
           "systemd-networkd-wait-online@.service"
           "systemd-networkd.service"
           "systemd-networkd.socket"
-          "systemd-networkd-persistent-storage.service"
+          "systemd-networkd-resolve-hook.socket"
           "systemd-networkd-varlink-metrics.socket"
+          "systemd-networkd-varlink.socket"
+          "systemd-networkd-persistent-storage.service"
         ];
 
         systemd.sockets.systemd-networkd-varlink-metrics.wantedBy = [ "sockets.target" ];
@@ -4314,6 +4316,9 @@ let
         systemd.additionalUpstreamUnits = [
           "systemd-networkd-wait-online.service"
           "systemd-networkd.service"
+          "systemd-networkd-resolve-hook.socket"
+          "systemd-networkd-varlink-metrics.socket"
+          "systemd-networkd-varlink.socket"
           "systemd-networkd.socket"
           "systemd-network-generator.service"
           "network-online.target"