Fix regression in vtkContourTriangulator
This reverts one part of a93fff6a (an infinite recursion fix) that caused a serious regression where polygons with more than one hole could end up with some holes missing after triangulation.
I went back to the test dataset for the infinite recursion to ensure that, at least on that dataset, the infinite recursion is still avoided even after this change.
This also fixes incorrect documentation for the TriangulatePolygon() method.
Closes #18566 (closed)
Backport: release
Edited by David Gobbi