applets/clipboard: Use FullTextRole in EditPage

The role can provide the untruncated text when the clipboard item being edited has
a very long text.

BUG: 448627

applets/clipboard/contents/ui/ClipboardPage.qml

@@ -176,7 +176,7 @@ Menu {
     onRemove: clipboardSource.service(uuid, "remove")
     onEdit: {
         stack.push(Qt.resolvedUrl("EditPage.qml"), {
-            text: clipboardMenu.model.get(clipboardMenu.view.currentIndex).DisplayRole,
+            text: clipboardMenu.model.get(clipboardMenu.view.currentIndex).FullTextRole,
             uuid: uuid
         });
     }