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FLASHING.md says how to take a newer version of the colleague's tree (copy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/position_updater.hpp

@@ -0,0 +1,56 @@
+#ifndef POSITION_UPDATER_HPP_KMWXTJRO
+#define POSITION_UPDATER_HPP_KMWXTJRO
+
+#include <vanetza/common/clock.hpp>
+#include <vanetza/units/frequency.hpp>
+
+namespace vanetza
+{
+
+// forward declarations
+class Runtime;
+class PositionProvider;
+namespace geonet { class Router; }
+
+namespace geonet
+{
+
+/**
+ * PositionUpdater helps updating a Router's position vector periodically
+ */
+class PositionUpdater
+{
+public:
+    /**
+     * Create PositionUpdater scheduling position updates read from position provider
+     * \note the default update rate is derived from router's MIB.
+     * \param runtime where updater schedules its callback
+     * \param pos position updates are read from this source
+     * \param router position sink
+     */
+    PositionUpdater(Runtime& runtime, PositionProvider& pos, Router& router);
+    ~PositionUpdater();
+
+    /**
+     * Change rate at which update is looking up new positions
+     * \note MIB setting is not affected
+     * \note an update interval smaller than zero disables updates
+     * \param interval update interval
+     */
+    void update_rate(Clock::duration interval);
+    void update_rate(units::Frequency);
+
+private:
+    void schedule();
+
+    Runtime& m_runtime;
+    PositionProvider& m_positioning;
+    Router& m_router;
+    Clock::duration m_interval;
+};
+
+} // namespace geonet
+} // namespace vanetza
+
+#endif /* POSITION_UPDATER_HPP_KMWXTJRO */
+