feat(bar): add music widget to bar layout

modules/bar/MusicWidget.qml

@@ -0,0 +1,17 @@
+pragma ComponentBehavior: Bound
+
+import qs.services
+import qs.ui
+
+BarButton {
+    id: root
+
+    readonly property string track: Media.trackArtist !== "" ? `${Media.trackTitle} — ${Media.trackArtist}` : Media.trackTitle
+    readonly property bool active: track !== ""
+
+    visible: active
+    hoverHighlight: false
+    pointerCursor: false
+    iconSource: Media.icon
+    label: `${Media.truncateText(root.track, 28)} ${Media.position} / ${Media.length}`
+}