Keep the colleague's microbu-esp32c5 tree in this repository

obu-firmware builds against vanetza-idf from microbu-esp32c5/external, but
that tree was gitignored, so a clone of this repository could not build the
firmware it ships. It is now committed here as ordinary files in its own
folder, microbu-esp32c5/: the colleague's commit cf4b99f plus the V2X2MAP
bridge's signature verification (--trust) used on the bench. Nothing is
fetched from or pushed to the colleague's repository; this repository and
its remotes carry everything. The folder's own .gitignore keeps build output,
downloaded components and private key material out, as it did there; the
committed file set is identical to that repository's tracked files.

The ESP32-C5 is still flashed from obu-firmware/, which only takes
vanetza-idf from microbu-esp32c5/, so the two stay separate folders.
FLASHING.md says how to take a newer version of the colleague's tree (copy
it over the folder, rebuild, test, commit).

microbu-esp32c5/external/vanetza-idf/vanetza/geonet/tests/position_updater.cpp

@@ -0,0 +1,109 @@
+#include <gtest/gtest.h>
+#include <vanetza/common/manual_runtime.hpp>
+#include <vanetza/common/position_provider.hpp>
+#include <vanetza/geonet/mib.hpp>
+#include <vanetza/geonet/position_updater.hpp>
+#include <vanetza/geonet/router.hpp>
+#include <chrono>
+
+using namespace vanetza;
+using namespace vanetza::geonet;
+using namespace std::chrono;
+
+class IncrementalPositionProvider : public PositionProvider
+{
+public:
+    const PositionFix& position_fix() override
+    {
+        next_position();
+        return position;
+    }
+
+private:
+    void next_position()
+    {
+        ++updates;
+        position.latitude = updates * 3.0 * units::degree;
+        position.longitude = updates * -1.5 * units::degree;
+        position.confidence.semi_minor = 25.0 * units::si::meter;
+        position.confidence.semi_major = 25.0 * units::si::meter;
+    }
+
+    unsigned updates = 0;
+    PositionFix position;
+};
+
+class PositionUpdaterTest : public ::testing::Test
+{
+public:
+    PositionUpdaterTest() :
+        router(runtime, mib), updater(runtime, positioning, router)
+    {
+    }
+
+    void SetUp() override
+    {
+        mib.itsGnSecurity = false; /*< no security entity required */
+        mib.itsGnMinimumUpdateFrequencyEPV = 1.0 * units::si::hertz;
+    }
+
+    unsigned lpv_updates()
+    {
+        units::GeoAngle latitude { router.get_local_position_vector().latitude };
+        return latitude.value() / 3;
+    }
+
+protected:
+    ManualRuntime runtime;
+    MIB mib;
+    Router router;
+    IncrementalPositionProvider positioning;
+    PositionUpdater updater;
+};
+
+TEST_F(PositionUpdaterTest, default_update_rate)
+{
+    EXPECT_EQ(0, lpv_updates());
+    runtime.trigger(milliseconds(950));
+    EXPECT_EQ(0, lpv_updates());
+    runtime.trigger(milliseconds(60));
+    EXPECT_EQ(1, lpv_updates());
+    runtime.trigger(seconds(1));
+    EXPECT_EQ(2, lpv_updates());
+    runtime.trigger(seconds(1));
+    EXPECT_EQ(3, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, custom_update_interval)
+{
+    updater.update_rate(seconds(10));
+    runtime.trigger(seconds(9));
+    EXPECT_EQ(0, lpv_updates());
+    runtime.trigger(seconds(1));
+    EXPECT_EQ(1, lpv_updates());
+    runtime.trigger(seconds(10));
+    EXPECT_EQ(2, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, custom_update_frequency)
+{
+    updater.update_rate(4.0 * units::si::hertz);
+    runtime.trigger(milliseconds(250));
+    EXPECT_EQ(1, lpv_updates());
+    runtime.trigger(milliseconds(250));
+    EXPECT_EQ(2, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, zero_hertz)
+{
+    updater.update_rate(0.0 * units::si::hertz);
+    runtime.trigger(seconds(60));
+    EXPECT_EQ(0, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, negative_interval)
+{
+    updater.update_rate(milliseconds(-200));
+    runtime.trigger(seconds(60));
+    EXPECT_EQ(0, lpv_updates());
+}