[AI] Add background to text sections of osd

The background is a solid color rectangle that is added for more
visiblility.

osd/PlayerControl.qml

@@ -171,28 +171,44 @@ Item {
     ColumnLayout {
       Layout.fillHeight: true
       spacing: 2
+      Layout.rightMargin: 8
+
+      Rectangle {
+        Layout.fillWidth: true
+        Layout.preferredHeight: 44
+        color: blendedColors.colSecondaryContainer
+        radius: 4
+
+        ColumnLayout {
+          id: titleBlock
+          spacing: 1
 
           StyledText {
             id: trackTitle
             Layout.fillWidth: true
+            Layout.leftMargin: 8
+            Layout.rightMargin: 8
             font.pixelSize: Appearance.font.pixelSize.large
-        color: blendedColors.colOnLayer0
+            color: blendedColors.colOnSecondaryContainer
             elide: Text.ElideRight
             text: playerController.player?.trackTitle || "Untitled"
           }
           StyledText {
             id: trackArtist
             Layout.fillWidth: true
+            Layout.leftMargin: 8
+            Layout.rightMargin: 8
             font.pixelSize: Appearance.font.pixelSize.smaller
-        color:blendedColors.colSubtext
+            color: blendedColors.colOnSecondaryContainer
             elide: Text.ElideRight
             text: playerController.player?.trackArtist
           }
+        }
+      }
       Rectangle {
         id: scrubberOutline
         Layout.fillWidth: true
         Layout.preferredHeight: 12
-        Layout.rightMargin: 8
         color: blendedColors.colSecondaryContainer
         visible: playerController.player?.length > 0
         radius: parent.height / 2