Adding simsun-extg font to support more character

[Kuldeep-MS]

Issue Description

Some Chinese characters are being displayed as boxes in WPF due to unavailability of the font.

Background Infromation

When text is rendered, each character's codepoint is searched in either the default font or the specified font. If the codepoint is not found, it falls back to composite fonts to locate the codepoint. These composite fonts are collections of different fonts that cover various codepoint ranges and are associated with different languages, enabling the rendering of characters.

Change Description

Adding Simsun-ExtG font and modifying the character range for the Simsun-ExtB font to GlobalUserInterface composite font. This will enable us to support more character from GB18030.

Customer Impact

all the characters will be displayed correctly, without this many of the Chinese characters will be displayed as boxes.

Regression

NA

Testing

In progress

Risk

Low

Microsoft Reviewers: Open in CodeFlow

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 11.22910%. Comparing base (b0f8705) to head (d91a106). Report is 98 commits behind head on main.

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #10517         +/-   ##
===================================================
- Coverage   11.39631%   11.22910%   -0.16721%     
===================================================
  Files           3353        3353                 
  Lines         668041      668041                 
  Branches       74980       74980                 
===================================================
- Hits           76132       75015       -1117     
- Misses        590563      591785       +1222     
+ Partials        1346        1241        -105     

Flag	Coverage Δ
Debug	11.22910% <ø> (-0.16721%)	:arrow_down:

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[miloush]

SimSun-ExtG ranges look OK to me now, they are block aligned.

[Kuldeep-MS]

/backport to release/8.0

[github-actions[bot]]

Started backporting to release/8.0: https://github.com/dotnet/wpf/actions/runs/15551475662

[Kuldeep-MS]

/backport to release/9.0

[github-actions[bot]]

Started backporting to release/9.0: https://github.com/dotnet/wpf/actions/runs/15551480615