Expand ground raise/lower tool to cover all basic LAT types

[ATHSE]

In order to avoid features being destroyed, we need to set a limit of what the tools will deform, and it makes most sense to enable it for all the LAT tiles, which we already know are 1x1.

...

Additionally, since RampBase and RampFix can be changed to match up with another tileset, for example "grass" in urban in SE, ideally there should be a way to force/override the default flat tile used when morphing the ground back to level. FA2 defaults to ClearTile, which is fine, but we should have the ability to pick an alternate tileset, also a 1x1, also logically a LAT tileset, but not critical to be one I would think?

Theaters.ini seems like the right place to add this override, and I could see it being practical to use both the tile group names defined at the very beginning of the theaters (GreenTile, SandTile, ClearTile, RoughTile) or the tileset number. If the implementation limits the ground morphing to just the LATs, then the naming is fine, if it's opened up to other 1x1 tilesets, then perhaps supporting both styles is best as the value.

Example theaters.ini entry:

[Urban]
ConfigINIPath=urban.ini
ContentMIXName=isourb.mix
TerrainPaletteName=isourb.pal
UnitPaletteName=uniturb.pal
FileExtension=.urb
NewTheaterBuildingLetter=U
MorphedToLevelTileset=GreenTile