[FEATURE] AutoScroll when signup fields are displayed

[ulrickpsp]

Is your feature request related to a problem? Please describe.
When signup button is clicked from loginView, the extra widgets shown are not centered in screen

Describe the solution you'd like
I'd like to auto scroll down when new widgets are shown and scroll up when they are hidden

Additional context
See images for better understanding:

Login:

Signup required:

Thanks a lot