* use INA3221 for bus voltage; fixes for telemetry variants
- add to sensors available for environment telemetry
(to report voltage/current)
- add vars to define channels to use for battery voltage
(for getBusVoltage) and environment metrics (default
to CH1 for both)
- write to the correct fields on the measurement struct
depending on the measurement variant, and DRY up the
sensor measurement collection code a bit
- this might be suitable for a common implementation for
the INA* sensors in a future PR...
* formatting
* derp
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Co-authored-by: Ben Meadors <benmmeadors@gmail.com>