Separate expansion control and worker threads

applications/services/expansion/expansion_worker.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <furi_hal_serial_types.h>
+
+typedef struct ExpansionWorker ExpansionWorker;
+
+typedef void (*ExpansionWorkerCallback)(void*);
+
+ExpansionWorker* expansion_worker_alloc(FuriHalSerialId serial_id);
+
+void expansion_worker_free(ExpansionWorker* instance);
+
+void expansion_worker_set_callback(
+    ExpansionWorker* instance,
+    ExpansionWorkerCallback callback,
+    void* context);
+
+void expansion_worker_start(ExpansionWorker* instance);
+
+void expansion_worker_stop(ExpansionWorker* instance);