QmlDesigner: Release MouseArea3D grab when hover leaves the parent view

Now we clear hovered state for MouseArea3D and remove it as a global
grabber instance when it gets HoverLeave event.

Fixes: QDS-13178
Change-Id: I8b69c39f54165fe1cb6f3dbaa75b19330446de77
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

src/tools/qml2puppet/qml2puppet/editor3d/mousearea3d.cpp

@@ -989,6 +989,12 @@ bool MouseArea3D::eventFilter(QObject *, QEvent *event)
 
         break;
     }
+    case QEvent::HoverLeave: {
+        setHovering(false);
+        if (s_mouseGrab == this && !dragging())
+            s_mouseGrab = nullptr;
+        break;
+    }
     default:
         break;
     }