Units disregarded in calculate API call when specifying irregularly spaced parameter array

For example, in this call:

cc.calculate(L=(np.logspace(1, 2, 9), "mm"))

the "mm" specified for L will be be silently ignored, and the units for L will instead be the default as loaded from the cavcalc config file.

To fix this I need to implement a way to specify units when a parameter is set to load its values from a file; as irregularly spaced arrays are currently supported via saving the data to a temporary file and loading later on in the command parsing step.