extract HoverableListItem component from list delegates

shell/applets/HoverableListItem.qml

@@ -0,0 +1,25 @@
+import QtQuick
+import "../services" as S
+
+Item {
+    id: root
+
+    readonly property bool hovered: _hover.hovered
+
+    width: parent?.width ?? 0
+    height: 32
+
+    Rectangle {
+        anchors.fill: parent
+        anchors.leftMargin: 4
+        anchors.rightMargin: 4
+        color: root.hovered ? S.Theme.base02 : "transparent"
+        radius: S.Theme.radius
+        z: -1
+    }
+
+    HoverHandler {
+        id: _hover
+        cursorShape: Qt.PointingHandCursor
+    }
+}