Apply color scheme to code browser tooltip

I used the QTextFrame interface to change the existing light theme colors to dark theme colors.

• do not force black on white palette
• adept colors when dark color scheme is used
  • make dark text colors brighter
  • when background color is set keep bg and fg colors

Same algorithm is also applied for the html in the quick open menu before the item is expanded.

Tooltip in Breeze Dark application color scheme

Quick open menu in Breeze Dark application color scheme

BUG: 257378