feat: add Hall effect, ADC, and encoder counter sensor classes

[ninankh]

Summary

Adds the base sensor class along with three sensor driver implementations:

• DRV5056 Hall effect sensor
• ADS114S0x ADC sensor
• LS7366R Encoder counter sensor

Unit tests are included for the base class and all three classes.

Changes

• base sensor class: shared interface/abstract methods used by the new sensor
• hall effect sensor: driver implementation
• adc sensor: driver implementation
• encoder counter sensor: driver implementation
• Unit tests added for each of the above under tests/

Testing

• Added pytest coverage for all four modules
• Ran make test locally, all passing
• Ran make check for lint/format compliance