Support drivers with python bindings

[sagarbhatt0904]

Add support for drivers in python bindings so we can run some simple simulations using python scripts and get stress strain plots and such. @hugary1995

[hugary1995]

@reverendbedford I'm tempted to defer this to pyzag. What do you think?

[reverendbedford]

It will run much faster if we use pyzag (because we can do the vectorized integration thing). On the other hand, it might make sense to have neml2 depend on pyzag and then implement the drivers in the neml2 namepsace (as they will be specific to us). That's probably the way to go and I'll add some simple examples after figure out wtf is up with AD.