Barracks art is now more centered and aligned with allied tent. Airfield is now more centered, which also makes the custom spawn position obsolete and fixes the misalignment between spawn and landing position.
This is also done to reduce misalignment between art and footprint-sized hit shapes that will follow later.
Removed top row of buildings where it only consisted of _ cells and adjusted the art offset instead. This fixes the issue that CenterPosition was located in the middle between the occupied and passable cell for defenses like tesla coils, makes their placement a bit more intuitive and makes setting up proper HitShapes easier.
Note: Removing Length: * from interior boxes and larvae as well as barrels
is intentional, boxes have just 1 frame, and frames 2+3 of larvae and
barrels are just duplicates of the first, added by Westwood to work around
damage stage issues.
Fixes fence palette on desert maps.
Removes final set of 16 sequences for all walls as it appears that these
are not actually supposed to be used as damage states for the actual
wall, but as end pieces for each wall. One of the pieces in particular
caused a single wall to be seen as invisible. Fixes#5654
