Prevent passing aux/opt vars to optim kwargs in theseus layer forward

[mhmukadam]

From discussion:

layer.forward(input_data={}, optimizer_kwargs={"verbose": True, "track_best_solution": True, "damping": 0.01, ..., etc })
After refactoring this way, I don't think we need to check at the if the keys passed to the dictionary are good or not. In fact, we should probably rename it to optimizer_options={} so it's pretty obvious what this dict is supposed to be doing.

[mhmukadam]

Closes #28