Doesn't work with recent flask-menu/flask

Package version (if known): 0.5.1

## Describe the bug
flask-menu no longer provides a register_menu (see https://github.com/inveniosoftware/flask-menu/issues/84), possibly a consequence of flask removing before_first_request. See also #56

I'm starting to think that this module is abandoned...

## Steps to Reproduce
1. Attempt to run the [Simple Example](https://flask-breadcrumbs.readthedocs.io/en/latest/#simple-example)

## Expected behavior
It at least tries to run.

## Screenshots (if applicable)

## Additional context
flask-menu 2.0.0
flask 3.1.0