0029135: 3D Offset algorithm produces a NULL shape

0029135: 3D Offset algorithm produces a NULL shape

UpdateValidEdges in BRepOffset_MakeOffset_1 - Perform the filtering of splits of the edges in two stages:
1. Separate filtering of the connected blocks using localized bounding edges taken only from the splits of offset faces from the block;
2. Combined treatment of the remaining splits using bounding edges from the splits of all offset faces.