Store Calibration Data in a Dynamic Format

[gbalke]

Currently, the calibration data structure is stored in the struct's byte form. This works fine as long as the data structure does not change. This is a problem as there will be more variables as the controller's functionality increases. To remedy this, protobufs may be a used as they can be grown and maintain backwards compatibility as long as field numbers are not re-used.

Steps to complete:

• Add protobuf build support
• Write https://github.com/BetzDrive/bldc-controller/blob/master/firmware/include/state.h into protobufs
• Adapt storing/loading of calibration in https://github.com/BetzDrive/bldc-controller/blob/master/firmware/src/state.cpp
• Adjust all calibration/state/parameter accesses (shouldn't really change as these are already dot accesses).

Testing/Verification:

• Unit test to verify loading of parameters (mock loading/storing from EEPROM).