metadata: Add metadata factory and implementation for integer types

Co-authored-by: Thomas Egerer <[email protected]>

src/libstrongswan/library.h

@@ -112,6 +112,7 @@
 #include "credentials/credential_factory.h"
 #include "credentials/credential_manager.h"
 #include "credentials/cred_encoding.h"
+#include "metadata/metadata_factory.h"
 #include "utils/chunk.h"
 #include "utils/capabilities.h"
 #include "utils/integrity_checker.h"
@@ -189,6 +190,11 @@ struct library_t {
 	 */
 	cred_encoding_t *encoding;
 
+	/**
+	 * Registry and factory for metadata creation
+	 */
+	metadata_factory_t *metadata;
+
 	/**
 	 * URL fetching facility
 	 */