Develop infrastructure for transfer functions

[arbennett]

We should provide some functionality which allows users to define transfer functions which map basin attributes to parameter values. This should be integrated in a way that you can initialize a new Simulation and use a function or method like apply_transfer_functions(tr_funs: Dict[str, callable], attributes: xr.Dataset, name: str='pysumma_transfer_funs') to assign the Simulation a new set of trial parameters, which automatically updates the file manager.

This should also operate seamlessly with the calibration routines. How to integrate this is TBD