SubGhz: add GFSK modulation, refactoring subghz_chat (#866)

* SubGhz: add GFSK modulation, refactoring subghz_chat
* SubGhz: off echo subghz_chat
* SubGhz: subghz_chat add sending and receiving formatted text, translation of the chat to events
* SubGhz: add UTF support in subghz_chat_worker_alloc

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

applications/subghz/helpers/subghz_chat.h

@@ -0,0 +1,29 @@
+#pragma once
+#include "../subghz_i.h"
+
+typedef struct SubGhzChatWorker SubGhzChatWorker;
+
+typedef enum {
+    SubghzChatEventNoEvent,
+    SubghzChatEventUserEntrance,
+    SubghzChatEventUserExit,
+    SubghzChatEventInputData,
+    SubghzChatEventRXData,
+    SubghzChatEventNewMessage,
+} SubghzChatEventType;
+
+typedef struct {
+    SubghzChatEventType event;
+    char c;
+} SubghzChatEvent;
+
+SubGhzChatWorker* subghz_chat_worker_alloc();
+void subghz_chat_worker_free(SubGhzChatWorker* instance);
+bool subghz_chat_worker_start(SubGhzChatWorker* instance, uint32_t frequency);
+void subghz_chat_worker_stop(SubGhzChatWorker* instance);
+bool subghz_chat_worker_is_running(SubGhzChatWorker* instance);
+SubghzChatEvent subghz_chat_worker_get_event_chat(SubGhzChatWorker* instance);
+void subghz_chat_worker_put_event_chat(SubGhzChatWorker* instance, SubghzChatEvent* event);
+size_t subghz_chat_worker_available(SubGhzChatWorker* instance);
+size_t subghz_chat_worker_read(SubGhzChatWorker* instance, uint8_t* data, size_t size);
+bool subghz_chat_worker_write(SubGhzChatWorker* instance, uint8_t* data, size_t size);