Changes to support openfe 1.0, gufe 1.0

[dotsdl]

There are changes in openfe and gufe for their respective 1.0 releases, in particular in Settings. These should be addressed in advance of a new feflow release.

@richardjgowers can give more insights into what has changed in these packages.

[IAlibay]

From an initial look, this is going to require a reasonably large amount of changes in the NEQ protocol, at least the way mappings are handled needs changing.

I've taken an initial test stab in #33 - happy to hand over as necessary @ijpulidos

[ijpulidos]

In order to keep things more modular and easier to understand I'm going to enumerate the things that will be needed for us to support 1.0 releases of gufe and openfe.

TODO:

• Fix IntegratorSettings
  • Make a new integrator settings class for NEQ integrator
• Fix solvation settings
  • should be just an import replacement
• Deal with mapping changes
  • SIngle mapping validation
  • Make sure everything is now a list rather than a dictionary
  • Remove dependency on "ligand" dictionary entry in mapping