GvR's Villager Variants

Additions:

• Added variants for Pillagers, Vindicators, Evokers, and Witches. Illusioners and Ravagers have not been given variants at the current moment.
• The eye colors for the illagers that have recieved variants are evoker green, vindicator blue, Minecraft Dungeons blue (very slightly darker version of vindicator blue), ultra dark brown, and ultra dark grey.
• The new eye color added for Witches is just a slightly lighter version of the original, taken from Minecraft Dungeons.