As paramters defined by energy_measurement instrument backends were not
used in instantiating the backends, but the underlying devlib
instrument, the values did not undergo the usual Plugin parameter
setting perocedure. In particuar, type conversion would not take place.
Make sure backend parameters are validated properly by setting them on
an obj_dict before passing them to the devlib instrument.
DerivedMeasurements in devlib was changed to return DerivedMetrics
instead of Measurements. The former do not have "channel" attribute, so
just pass its name to WA's metrics.
Delvib now is capable of performing postprocessing of MeasurementCSV
files, instead of calculating additional metrics in WA this will be
performed externally. Currently support has been added for calculating
average power and cumulative energy.