fix metadata.bind removal bug in sql alchemy 2.0

[ankona]

The metadata.bind property has been removed in SQLAlchemy 2.0. This fix allows passing an engine to enable performing index retrieval in sqla 2

[schettino72]

This worked for me as well. Just note that apart from the metadata parameter I had also to pass the engine parameter.

[Zlopez]

Closing this as it's already implemented in https://github.com/fschulze/sqlalchemy_schemadisplay/pull/35 which I merged