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/ber_decoder.h

@@ -0,0 +1,66 @@
+/*-
+ * Copyright (c) 2003-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	_BER_DECODER_H_
+#define	_BER_DECODER_H_
+
+#include "asn_application.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct asn_TYPE_descriptor_s;	/* Forward declaration */
+struct asn_codec_ctx_s;		/* Forward declaration */
+
+/*
+ * The BER decoder of any type.
+ * This function may be invoked directly from the application.
+ * Decodes BER, DER and CER data (DER and CER are different subsets of BER).
+ *
+ * NOTE: Use the der_encode() function (der_encoder.h) to produce encoding
+ * which is compliant with ber_decode().
+ */
+asn_dec_rval_t ber_decode(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor,
+    void **struct_ptr,  /* Pointer to a target structure's pointer */
+    const void *buffer, /* Data to be decoded */
+    size_t size         /* Size of that buffer */
+);
+
+/*
+ * Type of generic function which decodes the byte stream into the structure.
+ */
+typedef asn_dec_rval_t(ber_type_decoder_f)(
+    const struct asn_codec_ctx_s *opt_codec_ctx,
+    const struct asn_TYPE_descriptor_s *type_descriptor, void **struct_ptr,
+    const void *buf_ptr, size_t size, int tag_mode);
+
+/*******************************
+ * INTERNALLY USEFUL FUNCTIONS *
+ *******************************/
+
+/*
+ * Check that all tags correspond to the type definition (as given in head).
+ * On return, last_length would contain either a non-negative length of the
+ * value part of the last TLV, or the negative number of expected
+ * "end of content" sequences. The number may only be negative if the
+ * head->last_tag_form is non-zero.
+ */
+asn_dec_rval_t ber_check_tags(
+    const struct asn_codec_ctx_s *opt_codec_ctx, /* codec options */
+    const struct asn_TYPE_descriptor_s *type_descriptor,
+    asn_struct_ctx_t *opt_ctx, /* saved decoding context */
+    const void *ptr, size_t size,
+    int tag_mode,      /* {-1,0,1}: IMPLICIT, no, EXPLICIT */
+    int last_tag_form, /* {-1,0:1}: any, primitive, constr */
+    ber_tlv_len_t *last_length, int *opt_tlv_form /* optional tag form */
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _BER_DECODER_H_ */