T29335: [Segmentation] Show interactive warning for uninitialized render window geometry / {D774} provided a modernized approach for blocking render windows if the defined interaction reference geometry does not match the base renderer's world geometry.
In T29367#243284 it was decided that we should also do this for the StdMultiWidget, if we have a clean implementation and a user-friendly overlay warning.

Since this is now the case we could add this for the StdMultiWidget as well.

Note: The warning message and the UI style of the reinit button could be revised, the first draft was for bringing the whole concept into the develop / 2023.04 Release.