remove unused artwork
give the d2k tower rockets an angle

as the turrets points upwards
remove sandworm test that did not work out
move Tooltip into it's own CS file
remove failed experiment with fundaments
adjust the d2k production palette icon width to 60 again
adjust the d2k timer position a little
Merge pull request #3678 from Mailaender/d2k-early-merge

Non-controversial early merge cleanups from the native-r8s branch