fix: tray plugin can not drag

as title

Log: as title
pms: BUG-293871

Author: yixinshark

panels/dock/tray/package/TrayContainer.qml

@@ -143,8 +143,9 @@ Item {
         keys: ["text/x-dde-shell-tray-dnd-surfaceId"]
         onEntered: function (dragEvent) {
             let surfaceId = dragEvent.getDataAsString("text/x-dde-shell-tray-dnd-surfaceId")
-            console.log(surfaceId)
-            if (DDT.TraySortOrderModel.isDisplayedSurface(surfaceId)) {
+            let source = dragEvent.getDataAsString("text/x-dde-shell-tray-dnd-source")
+            console.log(surfaceId, source)
+            if (source !== "" && DDT.TraySortOrderModel.isDisplayedSurface(surfaceId)) {
                 dragEvent.accepted = false
             } else {
                 dragEvent.accepted = true

panels/dock/tray/quickpanel/DragItem.qml

@@ -22,7 +22,8 @@ Item {
     Component.onCompleted: {
         dragItem.Drag.mimeData = Qt.binding(function () {
             return {
-                "text/x-dde-shell-tray-dnd-surfaceId": root.dragTextData
+                "text/x-dde-shell-tray-dnd-surfaceId": root.dragTextData,
+                "text/x-dde-shell-tray-dnd-source": "quickPanel"
             }
         })
         dragItem.Drag.dragType = Drag.Automatic