py_wake.flow_map.FlowMap.power_xylk will not work with multidimensional P-CT-curves

The power_xylk method, calls the power method of WindTurbines with just the type kwarg. This will be insufficient if the WindTurbine obj has a multidimensional P-CT-curve, which needs more kwargs.

Also on line 81, why is there a restriction for type=0 ?

Maybe it should rather be:
type = {} if wt_type is None else {'type': wt_type} ?