Keep vanetza-idf in obu-firmware, so a plain clone builds the firmware

obu-firmware builds against the vanetza-idf C-ITS library, which until now
came from the colleague's microbu-esp32c5 tree beside the repository and was
not tracked here, so a clone of this repository could not build the firmware
it ships. The library alone is now part of obu-firmware, as
obu-firmware/external/vanetza-idf: their external/vanetza-idf at commit
cf4b99f, unchanged (9775 files; see its PROVENANCE.md). CMake takes it from
there by default; -DVANETZA_IDF_DIR still points the build elsewhere.

The rest of the colleague's tree (their own VAM firmware, PKI tooling,
station-link Python tools, the V2X2MAP bridge) stays out of this repository
and gitignored; nothing is pushed to their repository. NOTES.md, docs/06,
TODO.md and the pcap verifier's usage line point at the new location.

obu-firmware/external/vanetza-idf/vanetza/asn1/support/REAL_uper.c

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2017 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#include "asn_internal.h"
+#include "REAL.h"
+#include "OCTET_STRING.h"
+
+asn_dec_rval_t
+REAL_decode_uper(const asn_codec_ctx_t *opt_codec_ctx,
+                 const asn_TYPE_descriptor_t *td,
+                 const asn_per_constraints_t *constraints, void **sptr,
+                 asn_per_data_t *pd) {
+    (void)constraints;  /* No PER visible constraints */
+    return OCTET_STRING_decode_uper(opt_codec_ctx, td, 0, sptr, pd);
+}
+
+asn_enc_rval_t
+REAL_encode_uper(const asn_TYPE_descriptor_t *td,
+                 const asn_per_constraints_t *constraints, const void *sptr,
+                 asn_per_outp_t *po) {
+    (void)constraints;  /* No PER visible constraints */
+    return OCTET_STRING_encode_uper(td, 0, sptr, po);
+}