Update pyiron_workflow to 0.19.1

[jan-janssen]

@liamhuber I guess I need your help here. I was able to update to 0.18.0 as it still had the _legacy interface but with 0.19.X it is a whole new interface.

[liamhuber]

I think it's probably best to yank and re-write the examples? You can now write them natively in PWD, then convert PWD to flowrep and run that; in the reverse direction a pyiron_workflow node always has a flowrep .recipe, and flowrep has tools to convert to PWD. So we shouldn't need any more explicit glue here, we can always walk back and forth at the recipe level via a single call in each direction to the recipe converters in flowrep.tools

[liamhuber]

I was thinking and it should be super easy to add to_/from_pwd methods onto the Workflow class, just as convenience shortcuts to the flowrep converters. I can take care of that later

[jan-janssen]

I was thinking and it should be super easy to add to_/from_pwd methods onto the Workflow class, just as convenience shortcuts to the flowrep converters. I can take care of that later

That would be great - thanks a lot