[FL-2809] Rework BLE key storage (#2154)

* bt: disconnect first on profile change
* bt keys: rework bt keys
* saved struct: add payload size getter to API
* bt: rework bt with new key storage API
* bt: add keys storage operation to bt API
* hid: save bt keys on sd card
* bt: add unit tests for key storage
* bt: working profile switch
* bt: cleanup
* bt hid: change keys storage path

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

lib/toolbox/saved_struct.h

@@ -12,6 +12,12 @@ bool saved_struct_load(const char* path, void* data, size_t size, uint8_t magic,
 
 bool saved_struct_save(const char* path, void* data, size_t size, uint8_t magic, uint8_t version);
 
+bool saved_struct_get_payload_size(
+    const char* path,
+    uint8_t magic,
+    uint8_t version,
+    size_t* payload_size);
+
 #ifdef __cplusplus
 }
 #endif