Most of SourceGen uses standard WPF controls, which get their default
style from the system theme. The main disassembly list uses a
custom style, and always looks like the Windows default theme.
Some people greatly prefer white text on a black background, so we
now provide a way to get that. This also requires muting the colors
used for Notes, since those were chosen to contrast with black text.
This does not affect anything other than the ListView used for
code, because everything else can be set through the Windows
"personalization" interface. We might want to change the way the
Notes window looks though, to avoid having glowing bookmarks on
the side.