[FL-3664] 64k does not enough (#3216)

* Unit tests: add "exists" to furi_record tests
* Unit tests: mu_warn, storage 64k test
* Storage: read/write over 64k
* Unit tests: moar tests for storage r/w for >64k cases
* Apps, libs: replace uint16_t with size_t on storage r/w operations
* Unit tests: better data pattern, subghz: warning if transmission is prohibited

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

lib/music_worker/music_worker.c

@@ -396,7 +396,7 @@ bool music_worker_load_rtttl_from_file(MusicWorker* instance, const char* file_p
             break;
         };
 
-        uint16_t ret = 0;
+        size_t ret = 0;
         do {
             uint8_t buffer[65] = {0};
             ret = storage_file_read(file, buffer, sizeof(buffer) - 1);