Implementation of SoC Prediction

untested. Maybe revert to Jaspers Version

Core/Src/shunt_monitoring.c

@@ -70,3 +70,8 @@ void shunt_handle_can_msg(uint16_t id, const uint8_t *data) {
     break;
   }
 }
+
+int32_t shunt_getcurrent()
+{
+  return shunt_data.current;
+}