Store the color directly instead of the RGBA values

[mbarringer]

Currently, MarkupStyleColor stores the RGBA values directly, which doesn't work with dynamic colors, so toggling from white mode to dark mode leaves the text dark and illegible.

This PR changes MarkupStyleColor to store a provided UIColor or NSColor directly, rather than converting it to RGBA.

[zhgchgli0718]

Could you also take a look at the unit tests that are failing and fix them?, thank you.

[mbarringer]

The related unit tests are fixed to compare the colors directly, but the snapshot tests fail even against HEAD, so I don't think that has anything to do with my changes.

[zhgchgli0718]

I'll check it later, thank you.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (75f4f6d) 77.43% compared to head (a9ace27) 77.41%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #49      +/-   ##
==========================================
- Coverage   77.43%   77.41%   -0.02%     
==========================================
  Files         119      119              
  Lines        4343     4340       -3     
==========================================
- Hits         3363     3360       -3     
  Misses        980      980              

Files	Coverage Δ
...rkupParser/Core/MarkupStyle/MarkupStyleColor.swift	95.55% <100.00%> (-0.15%)	⬇️
...MarkupParserTests/Core/MarkupStyleColorTests.swift	100.00% <100.00%> (ø)
...MLTagStyleAttributeToMarkupStyleVisitorTests.swift	95.40% <100.00%> (ø)

[zhgchgli0718]

will release ASAP