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FLASHING.md says how to take a newer version of the colleague's tree (copy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

@@ -0,0 +1,87 @@
+#pragma once
+#include <vanetza/security/verify_service.hpp>
+
+namespace vanetza
+{
+
+// forward declaration
+class PositionProvider;
+class Runtime;
+
+namespace security
+{
+
+// forward declarations
+class Backend;
+
+namespace v2
+{
+
+// forward declarations
+class CertificateCache;
+class CertificateProvider;
+class CertificateValidator;
+class SignHeaderPolicy;
+
+} // namespace v2
+
+namespace v3
+{
+
+// forward declarations
+class CertificateCache;
+class CertificateProvider;
+class CertificateValidator;
+class SignHeaderPolicy;
+
+} // namespace v3
+
+/**
+ * Verify service with basic certificate and signature checks
+ */
+class StraightVerifyService : public VerifyService
+{
+public:
+    StraightVerifyService(const Runtime&, Backend&);
+    StraightVerifyService(const Runtime&, Backend&, PositionProvider&);
+
+    void use_certificate_cache(v2::CertificateCache*);
+    void use_certificate_provider(v2::CertificateProvider*);
+    void use_certificate_validator(v2::CertificateValidator*);
+    void use_sign_header_policy(v2::SignHeaderPolicy*);
+
+    void use_certificate_provider(v3::CertificateProvider*);
+    void use_certificate_cache(v3::CertificateCache*);
+    void use_certificate_validator(v3::CertificateValidator*);
+    void use_sign_header_policy(v3::SignHeaderPolicy*);
+
+    VerifyConfirm verify(const VerifyRequest&) override;
+    VerifyConfirm verify(const v2::SecuredMessage&);
+    VerifyConfirm verify(const v3::SecuredMessage&);
+
+private:
+    const Runtime& m_runtime;
+    Backend& m_backend;
+    PositionProvider* m_position_provider = nullptr;
+
+    struct {
+        v2::CertificateCache* m_cert_cache = nullptr;
+        v2::CertificateProvider* m_cert_provider = nullptr;
+        v2::CertificateValidator* m_cert_validator = nullptr;
+        v2::SignHeaderPolicy* m_sign_policy = nullptr;
+
+        constexpr bool complete() const
+        {
+            return m_cert_cache && m_cert_provider && m_cert_validator && m_sign_policy;
+        }
+    } m_context_v2;
+
+    struct {
+        v3::CertificateCache* m_cert_cache = nullptr;
+        v3::CertificateValidator* m_cert_validator = nullptr;
+        v3::SignHeaderPolicy* m_sign_policy = nullptr;
+    } m_context_v3;
+};
+
+} // namespace security
+} // namespace vanetza