Feature Request: Allow more than 1 perimeter and alternate extra perimeter on the base of a vase

[clfaye]

Hi - Cura has a couple of features that make the bases for vases more adaptable. First - A vase obviously has only 1 spiral perimeter. But - at its base you should be able to have more than one perimeter, which can lead to better looking bases with less visible seams. Cura lets you specify the wall thickness as more than 1 wall, uses that for the base, and then correctly only has 1 spiralized wall for the vase itself. Complementing this, Cura has an "alternate extra wall" feature that adds an extra wall every other layer on the base and really locks the bottom layers and perimeters together. This leads to rock solid and watertight vase bottoms. It would be great to add that to PrusaSlicer.