0029093: BOP PaveFiller hungs and constantly consumes memory

0029093: BOP PaveFiller hungs and constantly consumes memory

Method IntWalk_PWalking::ExtendLineInCommonZone(...) now is not called if the already found intersection point is on surface boundary.
As result, the intersection line going along any boundary will never be extended. It is appropriate for high-level OCCT-algorithm because they will take the boundary (not computed line) as intersection result.