Pathing for Giant Robots

Giant robots (like skyscraper high) should be able to work over any terrain slope if the height difference is within certain limit.
On the other hand, large cliff differences, like a canyon - cannot cross them.

This doesn't have to respect dynamic terrain changes, as we are talking very big terrain changes. So it may be not too hard to implement.

**Edit:**
This is of course very important feature for giant robots. Without it, they cannot move anywhere, getting stuck at each turn. Cannot make them all-terrain either, because there are large terrain features.

Start by locating the engine's terrain pathing and giant-robot movement entry points, then reproduce the reported case where a giant robot gets stuck at each turn. Define and test the intended boundary between slopes it can cross and canyon-sized height differences, including the stated assumption that dynamic terrain changes need not be handled.

Written by the indexing model from the issue text.