Investigate aligning Collector and Instrument Interfaces

[marcbonnici]

The instrument and collector APIs are currently distinct, investigate the possibility of aligning them to provide a more unified interface.

[douglas-raillard-arm]

+1 for a unified interface, there are a few energy meter instruments (equivalent) in LISA [1] that are currently bit-rotting. If the collector API was used for everything, they would probably be best contributed back to devlib and benefit from all the niceness coming with it (context manager etc)

[1] https://github.com/ARM-software/lisa/blob/master/lisa/energy_meter.py