Add support to CSSSupportsRule (#3661)
Add support to CSSSupportsRule (#3661)

- Add support to iterate over CSSRules of CSSSupportsRule.
- Checks if the CSS condition is supported.
- Resolves #3648
alexanderby/darkreader,alexanderby/darkreader,alexanderby/darkreader,darkreader/darkreader,darkreader/darkreader,darkreader/darkreader