Move RA World traits, FrozenUnderFog Modifier and various other traits into Traits
Adds editor categories to TD tilesets

Removes magenta desert tiles
Merge pull request #6979 from reaperrr/ra-reorg02

Moved various RA traits into Traits namespace & folders
Merge pull request #7043 from reaperrr/cnc-tileset-fix

Added map editor categories to TD tilesets