Based on a comment was post on offcanvas merge request, I did a first approach to decouple Backdrop from Modal, for further usage and to simplify Modal code.
It misses the extra tests and a class modification, but they can be done, if you like it
Preview: https://deploy-preview-32439--twbs-bootstrap.netlify.app/docs/5.0/components/modal/
TODO:
-
Revert the class name change since it's a breaking one -
Revert any further breaking changes like variable names, new backdrop.scss file etc