add picopass emulation

applications/external/picopass/loclass_writer.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+typedef struct LoclassWriter LoclassWriter;
+
+LoclassWriter* loclass_writer_alloc();
+
+void loclass_writer_free(LoclassWriter* instance);
+
+bool loclass_writer_write_start_stop(LoclassWriter* instance, bool start);
+
+bool loclass_writer_write_params(
+    LoclassWriter* instance,
+    uint8_t log_no,
+    const uint8_t csn[8],
+    const uint8_t epurse[8],
+    const uint8_t nr[4],
+    const uint8_t mac[4]);