Clean up nomad faction and pawn kind def, prefer inheritance

[hiergiltdiestfu]

Using inheritance did not work for the faction and the pawnkind, had to switch to full-copy.

_Originally posted by @hiergiltdiestfu in https://github.com/hiergiltdiestfu/NomadsLand/issues/8#issuecomment-1368242571

[hiergiltdiestfu]

RimWorld discord says the parents are not the defnames, but the xml class names, as per Name attribute

[hiergiltdiestfu]

Can't use xml inheritance from vanilla to the mod because basically all "leaf" nodes of the vanilla xml lack the Name attribute, so can't be referenced in ParentName 👎