Add board specific to Proton-C, with usual defaults turned on. (#10976)

- Set all other ChibiOS defaults to 'off', when not targeting Proton-C
- Modified all existing F303 boards to point at the QMK_PROTON_C to ensure repeatable binary output
- Modified version.h generation so that SKIP_VERSION=yes generates the same output

keyboards/acheron/shark/rules.mk

@@ -1,5 +1,6 @@
 # MCU name
 MCU = STM32F303
+BOARD = QMK_PROTON_C
 
 # Build Options
 #   change yes to no to disable