Fix torque cat wizard (do not merge yet)

Fixes #1166 

The culprit turned out to be the cumulative option that was removed a few days ago, that also accidentally removed the layer-type setting since it was located within the same meta-data.

As post-mortem, since the layer-type setting is crucial for the wizards to work, it should not be randomly set deep down in a form meta-data stuff to begin with. Unfortunately the related torque code is too convoluted to do a proper refactoring in a promptly manner. The changes here is the quick fix to make the functionality work again.