[Manual Registration] can't create multiple landmarks with zoom

[mathildemerle]

(on Ubuntu 20)

• Open the Registration workspace on Zoom mode (button top right if the app)
• Open 2 data in Manual registration
• Add a first landmark in the left view for instance, the landmark is displayed
• Try to add other landmarks -> you can't
• Change the zoom manually with the mouse in the view -> you can add landmarks

Then reopen the application, switch directly to Contrast mode

• If you try to add several landmarks, there are no problems.

The Zoom mode if it's not used creates a bug in Manual Registration.

[mathildemerle]

Some update for that issue:

• Windowing is an interactor created in medVtkViewItkDataImageInteractor::initParameters which is working great with Manual Registration toolbox.
• Zooming, Pan and Slicing are navigators created in medVtkViewNavigator::medVtkViewNavigator which bug in Manual Registration. All of them are blocking the creation of landmarks after the first one is created, until the user "activates" the navigator in the view, for instance zooming for the zoom.

I'm not sure why Windowing, Zooming, Pan and Slicing are not the same kind firstly. And perhaps, either in manualRegistrationToolBox, its startManualRegistration() method, or its controller, or in the way interactors and navigators are created, there is a problem