BUG: 441986

Make radio button layout behave like before; Fix random window resizing by reordering showing/hiding of buttons

(cherry picked from commit 3968515b)

(cherry picked from commit 12c15cf0)

Parent QWidget is not just used for memory management but also for
widget positioning.

Having as parent the main window rather than the direct parent widget,
makes the menu being positioned relative to the parent window under
Wayland.

It is an essential part of the app, consequently we want to make sure it is always shipped as part of it