Implement selection across multiple MessageDelegates

BUG: 457669

src/qml/Component/Timeline/MessageDelegate.qml

@@ -13,6 +13,13 @@ import org.kde.neochat 1.0
 TimelineContainer {
     id: messageDelegate
 
+    function positionAt(x, y) {
+        let point = label.mapFromItem(messageDelegate, x, y)
+        return label.positionAt(point.x, point.y)
+    }
+
+    property alias selectedText: label.selectedText
+
     property bool isEmote: false
     onOpenContextMenu: openMessageContext(model, label.selectedText, Controller.plainText(label.textDocument))
 
@@ -22,6 +29,7 @@ TimelineContainer {
             id: label
             Layout.fillWidth: true
             isEmote: messageDelegate.isEmote
+            isDelegate: true
         }
         Loader {
             id: linkPreviewLoader