Updated Air units navigator and locomotion (changes and fixes):
- Fixed Combine Manhack sometimes moving backwards all the time because the air unit blockers list was not cleared.
- Fixed air units not moving up when they encounter a cliff, and get stuck instead.
- Updated Strider to use the three foot position to determine the height. This fixes an issue with the Strider "flying up" when moving around a tree. Additional the Strider height is clamped to a max height.