Custom fonts are not used as no parameter for fontFamilyFallback

[dtruong27]

Is your feature request related to a problem? Please describe.
Although in the description of fontFamily in the CodeEditorStyle, fontFamilyFallback is mentioned, it is not a parameter of the class. Therefore, there is no way to pass the custom fonts that are defined in the pubspec.yaml.

    - family: NotoSans
      fonts:
        - asset: assets/fonts/NotoSans-Light.ttf
          weight: 300
        - asset: assets/fonts/NotoSans-Regular.ttf
          weight: 400

Describe the solution you'd like
In the baseStyle

final TextStyle baseStyle = TextStyle(
      fontSize: widget.style?.fontSize ?? _kDefaultTextSize,
      fontFamily: widget.style?.fontFamily,
      height: widget.style?.fontHeight ?? _kDefaultFontHeight,
    );

the fontFamilyFallback should be inherited from the ThemeData of the MaterialApp.

Describe alternatives you've considered
Alternatively, fontFamilyFallback can also be defined as a parameter of the CodeEditorStyle.

Additional context
By default, the system fonts are used as fallback. However, this does not work for flutter web when we have a content security policy that prevents loading external resources.