[FL-580] Prepare BLE for certification (#376)

* api-hal-bt: separate bt init to core init and app start

* bt: add continuous TX and RX tests

* bt: finish rx test on Back button click

* api-hal-bt: check core 2 started, same f4 and f5 implementation

* bt: refactoring, move hopping test logic to main thread

Co-authored-by: あく <alleteam@gmail.com>

applications/bt/bt.h

@@ -1 +1,3 @@
 #pragma once
+
+typedef struct Bt Bt;