Motor preset smart selection shortcut

[ZLLentz]

Add feature to motor presets to automatically select which preset category to use based on context.

Original card:
motor.preset('in') should dispatch to either add_hutch or add_exp depending on whether its an experiment specific motor (in the x namespace?)

Note from Zach: remember that motor presets in pcdsdevices make no assumption that there are two categories (hutch, exp), in fact you could have one category or seven if you wanted. So we may need to allow hutch-python to pass in its own heuristics for determining which category to use when someone calls the shortcut.