First draft of ListView custom GroupHeader painting.

[KlausLoeffelmann]

The ListView lacks the ability to configure certain visual aspects of group headers, like the GroupHeader font color. That said, this is the prototype to utilize the ListView's principle mechanism to custom draw group headers.

Microsoft Reviewers: Open in CodeFlow

[codecov]

Codecov Report

Attention: Patch coverage is 4.23729% with 113 lines in your changes missing coverage. Please review.

Project coverage is 76.81500%. Comparing base (e037b05) to head (f5c1dc2).
Report is 23 commits behind head on main.

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #13708         +/-   ##
===================================================
+ Coverage   76.75572%   76.81500%   +0.05928%     
===================================================
  Files           3256        3258          +2     
  Lines         642016      642700        +684     
  Branches       47548       47582         +34     
===================================================
+ Hits          492784      493690        +906     
+ Misses        145574      145349        -225     
- Partials        3658        3661          +3     

Flag	Coverage Δ
Debug	76.81500% <4.23729%> (+0.05928%)	⬆️
integration	18.98060% <3.38983%> (-0.01117%)	⬇️
production	51.41888% <4.23729%> (+0.10054%)	⬆️
test	97.41822% <ø> (+0.00103%)	⬆️
unit	48.79892% <4.23729%> (+0.10229%)	⬆️

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