[Dashboard] Realize custom font manager to override default one in avalonia

[Dynesshely]

🪦 Is your feature request related to a problem? Please describe.

Issues:

• [Dashboard] Arch Linux 上应用无法启动 #109 .
• [Dashboard] Arch Linux 上无法运行 #263 .

Avalonia try to load a font that dosen't exists on some platforms.

KitX did embedded fonts to use, accroding to AvaloniaUI/Avalonia#4760 , we can provide a custom font manager to override avalonia one to avoid load unnecessary font.

🪧 Describe the solution you'd like

Provide custom font manager class, and register it at App.xaml.cs.

🧾 Describe alternatives you've considered

No response

📎 Additional context

No response

[github-actions]

Tracked by #223 .

[Dynesshely]

View similar situations: https://www.cnblogs.com/joyandjoys/p/14346935.html

[Dynesshely]

Add new source link: https://github.com/AvaloniaUI/Avalonia/blob/master/tests/Avalonia.Skia.UnitTests/Media/CustomFontManagerImpl.cs