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/LocationsPage.qml

@@ -0,0 +1,72 @@
+// SPDX-FileCopyrightText: 2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+import QtQuick
+import QtLocation
+import QtPositioning
+
+import org.kde.kirigami as Kirigami
+import org.kde.neochat
+
+Kirigami.Page {
+    id: root
+
+    required property var room
+
+    title: i18nc("Locations on a map", "Locations")
+
+    padding: 0
+
+    MapView {
+        id: mapView
+        anchors.fill: parent
+        map.plugin: OsmLocationPlugin.plugin
+        visible: mapView.map.mapItems.length !== 0
+
+        map.center: {
+            let c = LocationHelper.center(LocationHelper.unite(locationsModel.boundingBox, liveLocationsModel.boundingBox));
+            return QtPositioning.coordinate(c.y, c.x);
+        }
+        map.zoomLevel: {
+            const zoom = LocationHelper.zoomToFit(LocationHelper.unite(locationsModel.boundingBox, liveLocationsModel.boundingBox), mapView.width, mapView.height)
+            return Math.min(Math.max(zoom, map.minimumZoomLevel), map.maximumZoomLevel);
+        }
+
+        MapItemView {
+            Component.onCompleted: mapView.map.addMapItemView(this)
+            anchors.fill: parent
+
+            model: LocationsModel {
+                id: locationsModel
+                room: root.room
+            }
+            delegate: LocationMapItem {
+                isLive: false
+                heading: NaN
+            }
+        }
+
+        MapItemView {
+            Component.onCompleted: mapView.map.addMapItemView(this)
+            anchors.fill: parent
+            model: LiveLocationsModel {
+                id: liveLocationsModel
+                room: root.room
+            }
+            delegate: LocationMapItem {}
+        }
+
+        Connections {
+            target: mapView.map
+            function onCopyrightLinkActivated(link: string) {
+                Qt.openUrlExternally(link);
+            }
+        }
+    }
+
+    Kirigami.PlaceholderMessage {
+        text: i18n("There are no locations shared in this room.")
+        visible: mapView.map.mapItems.length === 0
+        anchors.centerIn: parent
+    }
+}