Updating pathing grid, pathfinding with different sized units, pathing grid fixes

[spudde123]

• Pathfinding now allows to query with unit sizes x <= 1 and 1 < x <= 2
• Pathfinding starting and end points are adjusted if they are inside some nonpathable thing such as a building or rocks. The new start or end point will be the closest pathable point, prioritizing points on the same terrain height level first before looking at other points
• Pathing grids update during the game and mostly without much work
• Pathing grid is also now much more accurate. The attempt is to represent each unit with precisely the right size instead of circles that are roughly correct
• Creating new pathing grids when requested is much faster because we don't need to loop over the destructables
• Fixed air_grid and air_vs_ground_grid having areas out of map bounds as pathable
• Test for whether different destructables in maps are handled already