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
The format is almost identical to CL2, except it uses the frame header
to store frame width and height instead of 5 32-line offsets.
This means we always have access to frame dimensions, so we can use it
as an on-disk format for our graphics as well.
Additionally, we may be able to optimize the rendering even more
in the future now that we have guaranteed knowledge of frame dimensions.