Spell ALLEGRO_DST_COLOR, ALLEGRO_INVERSE_DST_COLOR with "DEST".

To match ALLEGRO_SRC_MINUS_DEST and ALLEGRO_DEST_MINUS_SRC.
Leave compatibility defines as the old names have been around
for a while, and probably see some use.
tests: Support ALLEGRO_*_COLOR blending modes in test_driver.
tests: Test ALLEGRO_*_COLOR blending modes.

I did NOT check these tests by hand.  They might not make any sense.
Fix bug which meant ALLEGRO_INVERSE_SRC_COLOR and
ALLEGRO_INVERSE_DEST_COLOR never actually worked on D3D.

Sloppy.
Fix maintenance problem in d3d_al_blender_to_d3d.

Also avoid a linear search.
Assert al_set_blender, al_set_separate_blender parameters.