New Ancient Lich baseframe and updated animations by shadowm

This version of the commit keeps the orphaned melee attack animation
frame, which is superseded by a 2-frame set. The orphaned frame is a
copy of the new first frame, for compatibility with existing add-ons.
The 1.13.x version of this commit removes it entirely.

Animation WML and art reference taken from the existing L3 Lich.