feat(bar): add network widget and service

modules/bar/NetworkWidget.qml

@@ -0,0 +1,11 @@
+pragma ComponentBehavior: Bound
+
+import qs.ui
+import qs.services
+
+BarButton {
+    hoverHighlight: false
+    pointerCursor: false
+    label: Network.statusText
+    iconSource: Network.icon
+}