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/tools/docker/build_and_run_tests.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+set -e
+SCRIPT=$(readlink -f $0)
+SCRIPT_PATH=$(dirname $SCRIPT)
+ROOT=${1:-$SCRIPT_PATH/../..}
+ROOT_PATH=$(readlink -f ${ROOT})
+BUILD_DIR=${BUILD_DIR:-$PWD/build}
+
+mkdir -p ${BUILD_DIR} && cd ${BUILD_DIR}
+cmake -G Ninja \
+    -DVANETZA_WITH_CRYPTOPP=ON \
+    -DVANETZA_WITH_OPENSSL=ON \
+    -DBUILD_CERTIFY=ON \
+    -DBUILD_PKI=ON \
+    -DBUILD_SOCKTAP=ON \
+    -DBUILD_TESTS=ON \
+    -DGTest_BUILD_DIRECTORY_DOWNLOAD=ON \
+    ${ROOT_PATH}
+cmake --build .
+ctest --output-on-failure