Onboard ADC driver redundantly converts every single ADC channel

In GitLab by @matthew.morley.ca on Mar 29, 2023, 18:34

The ADCs are currently set up so that a whole bunch of channels are grouped together into a single conversion. However, for every single pyro continuity and battery voltage "device", we re-call convert on EVERY channel attached to that `hadc`, and then just extract the n-th value from that.

This will require a refactor to seperate concerns a bit, but we should only call `adcDev_startSingleRead` *once per hadc instance*, and then adcDev_getValue *once per input we care about*. This means that adc dev will need to support an unknown number of inputs, and somewhere in `hardware_manager` we'll need to handle the plumbing from the result array into pyro continuity channel numbers and stuff.