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/geonet/data_indication.hpp

@@ -0,0 +1,41 @@
+#ifndef DATA_INDICATION_HPP_DOJK9Q8T
+#define DATA_INDICATION_HPP_DOJK9Q8T
+
+#include <vanetza/common/byte_buffer.hpp>
+#include <vanetza/common/its_aid.hpp>
+#include <vanetza/geonet/destination_variant.hpp>
+#include <vanetza/geonet/interface.hpp>
+#include <vanetza/geonet/position_vector.hpp>
+#include <vanetza/security/decap_service.hpp>
+#include <boost/optional.hpp>
+
+namespace vanetza
+{
+namespace geonet
+{
+
+/**
+ * \brief GN-DATA.indication
+ * \see EN 302 636-4-1 V1.4.1, section J.4
+ */
+struct DataIndication
+{
+    UpperProtocol upper_protocol;
+    TransportType transport_type;
+    DestinationVariant destination;
+    ShortPositionVector source_position;
+    security::DecapReport security_report;
+    boost::optional<ItsAid> its_aid;
+    boost::optional<ByteBuffer> permissions;
+    // TS 102 723-8 V2.0.0 clause 5 incorporates V1.1.1 Table 27:
+    // preserve the optional SN-DECAP certificate_id through NF-SAP.
+    boost::optional<security::HashedId8> certificate_id;
+    TrafficClass traffic_class;
+    boost::optional<Lifetime> remaining_packet_lifetime;
+    boost::optional<unsigned> remaining_hop_limit;
+};
+
+} // namespace geonet
+} // namespace vanetza
+
+#endif /* DATA_INDICATION_HPP_DOJK9Q8T */