…nal data

Summary of the changes/fixes:

1. Trigger checkbox and radio click events identically (cherry-picked from
   b442aba that was reverted before).
2. Manually trigger a native event before checkbox/radio handlers.
3. Add test coverage for triggering namespaced native-backed events.
4. Propagate extra parameters passed when triggering the click event to
   the handlers.
5. Intercept and preserve namespaced native-backed events.
6. Leverage native events for focus and blur.
7. Accept that focusin handlers may fire more than once for now.

Fixes jquerygh-1741
Fixes jquerygh-3423
Fixes jquerygh-3751
Fixes jquerygh-4139
Closes jquerygh-4279
Ref jquerygh-1367
Ref jquerygh-3494

Summary

Checklist

• All authors have signed the CLA at https://cla.js.foundation/jquery/jquery
• New tests have been added to show the fix or feature works
• Grunt build and unit tests pass locally with these changes
• If needed, a docs issue/PR was created at https://github.com/jquery/api.jquery.com