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/CollapsedRoomDelegate.qml

@@ -0,0 +1,52 @@
+// SPDX-FileCopyrightText: 2023 Carl Schwan <carl@carlschwan.eu>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+import QtQuick
+import QtQuick.Controls as QQC2
+import QtQuick.Layouts
+import QtQml.Models
+
+import org.kde.kirigami as Kirigami
+import org.kde.kirigamiaddons.labs.components as KirigamiComponents
+import org.kde.kitemmodels
+
+import org.kde.neochat
+
+QQC2.ItemDelegate {
+    id: root
+
+    required property NeoChatRoom currentRoom
+    required property bool categoryVisible
+    required property string filterText
+    required property url avatar
+    required property string displayName
+
+    topPadding: Kirigami.Units.largeSpacing
+    leftPadding: Kirigami.Units.largeSpacing
+    rightPadding: Kirigami.Units.largeSpacing
+    bottomPadding: Kirigami.Units.largeSpacing
+
+    width: ListView.view.width
+    height: visible ? ListView.view.width : 0
+
+    visible: root.categoryVisible || filterText.length > 0
+
+    contentItem: KirigamiComponents.Avatar {
+        source: root.avatar
+        name: root.displayName
+
+        sourceSize {
+            width: Kirigami.Units.gridUnit + Kirigami.Units.largeSpacing * 2
+            height: Kirigami.Units.gridUnit + Kirigami.Units.largeSpacing * 2
+        }
+    }
+
+    onClicked: RoomManager.resolveResource(currentRoom.id)
+
+    Keys.onEnterPressed: RoomManager.resolveResource(currentRoom.id)
+    Keys.onReturnPressed: RoomManager.resolveResource(currentRoom.id)
+
+    QQC2.ToolTip.visible: text.length > 0 && hovered
+    QQC2.ToolTip.text: root.displayName ?? ""
+    QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
+}