Last major update

Updating all of these.

Found out the STM32L has horrible timing, I will need to get a crystal
that's accurate enough before development can continue

[Firmware changes]
[bsp.h/bsp.c]
* Added some functions for a clock feature (this was to check for
accuracy)
* Changed the TIM2 interrupt for the new way the MCU is supposed to
request and process notes.

[bsp_io.h]
* Added more defines for pinouts.

[cmd_msg_rx.c]
* Redid the message handler function.