Caused by reusing icons from the main editor in the code editor. These
icons were converted based on the main editor theme and not the code
editor theme.
- Create new icons for use specifically in the code editor
- Add these icons to the exceptions when converting dark theme icons
to light theme automatically
- Change the default value of the code folding color to match previous
color
- Code folding icon is now pure white by default to correctly match
the color defined in settings
