Swap groundstation stm32 project to use common ground station class

There's a class here: https://github.com/AerospaceNU/stm32-avionics/blob/main/common/groundstation/groundstation.h that was added so we can have Arduino ground stations. It should be a pretty direct copy-paste of the current STM32 ground station code. We want to swap over the STM32 ground station code to use this so that the code only lives in one spot. Also, this might make life easier if/when we start writing code for the new groundstation boards.