Move remaining code to app module

There's still some stuff that could potentially go elsewhere but I think it's enough for now.

src/app/qml/AvatarNotification.qml

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2024 James Graham <james.h.graham@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+
+import QtQuick
+import QtQuick.Controls as QQC2
+
+import org.kde.kirigami as Kirigami
+import org.kde.kirigamiaddons.labs.components as KirigamiComponents
+
+KirigamiComponents.Avatar {
+    id: root
+
+    property int notificationCount
+
+    property bool notificationHighlight
+
+    property bool showNotificationLabel
+
+    QQC2.Label {
+        id: notificationCountLabel
+        anchors.top: parent.top
+        anchors.right: parent.right
+        anchors.topMargin: -Kirigami.Units.smallSpacing
+        anchors.rightMargin: -Kirigami.Units.smallSpacing
+        z: 1
+        width: Math.max(notificationCountTextMetrics.advanceWidth + Kirigami.Units.smallSpacing * 2, height)
+        height: Kirigami.Units.iconSizes.smallMedium
+
+        text: root.notificationCount > 0 ? root.notificationCount : ""
+        visible: root.showNotificationLabel
+        color: Kirigami.Theme.textColor
+        horizontalAlignment: Text.AlignHCenter
+        verticalAlignment: Text.AlignVCenter
+        background: Rectangle {
+            visible: true
+            Kirigami.Theme.colorSet: Kirigami.Theme.Button
+            Kirigami.Theme.inherit: false
+            color: root.notificationHighlight ? Kirigami.Theme.positiveTextColor : Kirigami.Theme.backgroundColor
+            radius: height / 2
+        }
+
+        TextMetrics {
+            id: notificationCountTextMetrics
+            text: notificationCountLabel.text
+        }
+    }
+}