vici: Directly provide CA certificates in authority sections

With the previous approach, CA certificates that were not re-loaded via
load-cert() (e.g. from tokens or via absolute paths) would not be available
anymore after the clear-creds() command was used.  This avoids this
issue, but can cause duplicate CA certificates to get stored and enumerated,
so there might be a scaling factor.

src/libcharon/plugins/vici/vici_authority.h

@@ -46,10 +46,8 @@ struct vici_authority_t {
  * Create a vici_authority instance.
  *
  * @param dispatcher		dispatcher to receive requests from
- * @param cred				in-memory credential backend managed by VICI
  * @return					authority backend
  */
-vici_authority_t *vici_authority_create(vici_dispatcher_t *dispatcher,
-										vici_cred_t *cred);
+vici_authority_t *vici_authority_create(vici_dispatcher_t *dispatcher);
 
 #endif /** VICI_AUTHORITY_H_ @}*/