[feat] Add helper function to display a dialog on the same window as the application

On windows OS, displaying a dialog on the pqLidarViewManager::instance()->getMainWindow() does not ensure to have it on the current windows. If the mainWindow has been moved from a screen to another, some dialog will pop up on the previous screen This function ensure that the dialog pop up on the right screen.

That's an issue we already had for some dialog in paraview :
in PV5.6 : bjacquet/paraview@462a742d
in PV5.4 : bjacquet/paraview@fd68face