Fix Drag Drop from splits in Wayland

In wayland we cant use QCursor::position, it will always
return a bogus value

src/TerminalDisplay.cpp

@@ -574,9 +574,8 @@ void TerminalDisplay::hideDragTarget()
     update();
 }
 
-void TerminalDisplay::showDragTarget()
+void TerminalDisplay::showDragTarget(const QPoint& cursorPos)
 {
-    auto cursorPos = mapFromGlobal(QCursor::pos());
     using EdgeDistance = std::pair<int, Qt::Edge>;
     auto closerToEdge = std::min<EdgeDistance>(
         {

src/TerminalDisplay.h

@@ -74,7 +74,7 @@ public:
     explicit TerminalDisplay(QWidget *parent = nullptr);
     ~TerminalDisplay() Q_DECL_OVERRIDE;
 
-    void showDragTarget();
+    void showDragTarget(const QPoint& pos);
     void hideDragTarget();
 
     void applyProfile(const Profile::Ptr& profile);

src/ViewSplitter.cpp

@@ -307,7 +307,8 @@ void Konsole::ViewSplitter::dragMoveEvent(QDragMoveEvent* ev)
             return;
         }
         currentDragTarget = terminal;
-        currentDragTarget->showDragTarget();
+        auto localPos = currentDragTarget->mapFromParent(ev->pos());
+        currentDragTarget->showDragTarget(localPos);
     }
 }