FL-339: cli diagnostic interface for power subsystem. (#256)

* Core, API: add externs for c++
* Makefile: improve debug speed, flash with openocd, cleanup f2 config
* Power: add cli diagnostic.
* Local: fix api hal externs
* Local: fix externs in main and flipper_hal
* F2: power state dump stabs
* Bootloader flashing with openocd
* F3: move bq drivers to libs
* temporary do not build drivers on local
* temporary do not build drivers on f2

Co-authored-by: aanper <mail@s3f.ru>

firmware/targets/api-hal-include/api-hal-delay.h

@@ -1,6 +1,14 @@
 #pragma once
 #include "main.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void delay(float milliseconds);
 void delay_us(float microseconds);
 void delay_us_init_DWT(void);
+
+#ifdef __cplusplus
+}
+#endif