This modifies the previous support for grayscale
and LMS-based simulation for protanopia and
deuteranopia, and brings it in line with the
methodology currently used in Chromium and Firefox
(https://bugs.chromium.org/p/chromium/issues/detail?id=1003700,
https://bugzilla.mozilla.org/show_bug.cgi?id=1655053).
QGIS now uses updated grayscale luminance
calculations (renamed to achromatopsia), a
precomputed protanopia matrix (renamed from
protanope), a precomputed deuteranopia matrix
(renamed from deuteranope), and an additional mode
for tritanopia using a similarly precomputed matrix.
This commit addresses issue #29760.
