Revert "Revert Deep Sleep due to BLE issues and other random freezes"

This reverts commit addf909287.

firmware/targets/furi_hal_include/furi_hal_debug.h

@@ -18,6 +18,9 @@ void furi_hal_debug_enable();
 /** Disable MCU debug */
 void furi_hal_debug_disable();
 
+/** Check if GDB debug session is active */
+bool furi_hal_debug_is_gdb_session_active();
+
 #ifdef __cplusplus
 }
 #endif