0027596: Visualization, StdPrs_WFShape - pack isolines into single group of primitives

0027596: Visualization, StdPrs_WFShape - pack isolines into single group of primitives

StdPrs_ShadedShape, computeFaceBoundaries() now does not create additional temporary buffer for edges.
StdPrs_Isolines::AddOnTriangulation() now reconstacts polylines from segments projected onto triangulation.

StdPrs_WFShape::Add() now packs isolines into single group in presentation (instead of per-face group).
Even more - StdPrs_WFShape now groups lines with the same aspects.

Prs3d_Drawer::UIsoAspect(), ::VIsoAspect(), ::VIsoAspect() - default width
has been changed from 0.5 to 1.0.