adjust clock.shp to the Dune 2000 icon size

remove artifacts from automatic palette conversions
Merge pull request #7085 from Mailaender/d2k-clock

Fixed color and overlap glitches in the Dune 2000 build palette
Added a trait for PoisonedByTerrain, replaces PoisonedByTiberium with a more flexible name and allows poisoning by more than resources.
Removed obsolete PoisonedByTiberium
Added upgrade rules