extract OsdSection base component from Volume and Backlight modules

shell/modules/VolumeModule.qml

@@ -5,10 +5,10 @@ import "." as M
 import "../services" as S
 import "../applets" as C
 
-M.BarSection {
+M.OsdSection {
     id: root
     spacing: S.Theme.moduleSpacing
-    tooltip: ""
+    _panelHovered: hoverPanel.panelHovered
 
     PwObjectTracker {
         objects: [Pipewire.defaultAudioSink, ...root._streamList]
@@ -40,36 +40,22 @@ M.BarSection {
         return streams;
     }
 
-    property bool _osdActive: false
     property bool _volumeInit: false
     property bool _mutedInit: false
-    readonly property bool _anyHover: root._hovered || hoverPanel.panelHovered
-    readonly property bool _showPanel: _anyHover || _osdActive
 
     onVolumeChanged: {
         if (!_volumeInit) {
             _volumeInit = true;
             return;
         }
-        _flashPanel();
+        flashPanel();
     }
     onMutedChanged: {
         if (!_mutedInit) {
             _mutedInit = true;
             return;
         }
-        _flashPanel();
-    }
-
-    function _flashPanel() {
-        _osdActive = true;
-        _osdTimer.restart();
-    }
-
-    Timer {
-        id: _osdTimer
-        interval: 1500
-        onTriggered: root._osdActive = false
+        flashPanel();
     }
 
     M.BarIcon {