Inlines blit command parsing.
We previously had blit commands because we supported rendering multiple
formats (CEL, CL2, CLX) but now we only ever render CLX, so this is
no longer necessary.
Original Blizzard encoder is slightly less optimal than our encoder.
While size in RAM in less of a concern for the non-`UNPACKED_MPQS`
build, smaller files are faster to render.
Savings for unpacked and minified MPQs:
* diabdat.mpq: 918,311 bytes.
* hellfire.mpq: 313,882 bytes.
Example player graphics (note that only a few are loaded at any given time for single player):
* diabdat/plrgfx/warrior/: 366,564 bytes.
Example monster graphics savings:
* diabdat/monsters/skelbow: 5,391 bytes.
Based on the implementation from https://github.com/diasurgical/devilutionx-graphics-tools/pull/6
Gleb Mazovetskiy