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/its/PhoneNumber.h

@@ -0,0 +1,48 @@
+/*
+ * Generated by asn1c
+ * From ASN.1 module "ITS-Container"
+ * 	found in "TS102894-2v131-CDD.asn"
+ * 	`asn1c -fcompound-names -fincludes-quoted -no-gen-example -R`
+ */
+
+#ifndef	_PhoneNumber_H_
+#define	_PhoneNumber_H_
+
+
+#include "asn_application.h"
+
+/* Including external dependencies */
+#include "NumericString.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* PhoneNumber */
+typedef NumericString_t	 PhoneNumber_t;
+
+/* Implementation */
+extern asn_oer_constraints_t asn_OER_type_PhoneNumber_constr_1;
+extern asn_per_constraints_t asn_PER_type_PhoneNumber_constr_1;
+extern asn_TYPE_descriptor_t asn_DEF_PhoneNumber;
+asn_struct_free_f PhoneNumber_free;
+asn_struct_print_f PhoneNumber_print;
+asn_constr_check_f PhoneNumber_constraint;
+ber_type_decoder_f PhoneNumber_decode_ber;
+der_type_encoder_f PhoneNumber_encode_der;
+xer_type_decoder_f PhoneNumber_decode_xer;
+xer_type_encoder_f PhoneNumber_encode_xer;
+jer_type_encoder_f PhoneNumber_encode_jer;
+oer_type_decoder_f PhoneNumber_decode_oer;
+oer_type_encoder_f PhoneNumber_encode_oer;
+per_type_decoder_f PhoneNumber_decode_uper;
+per_type_encoder_f PhoneNumber_encode_uper;
+per_type_decoder_f PhoneNumber_decode_aper;
+per_type_encoder_f PhoneNumber_encode_aper;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _PhoneNumber_H_ */
+#include "asn_internal.h"