New certificate_authorities functions

Add functions to add/retrieve the certificate_authorities. The older
client_CA functions mainly just call the new versions now.

Rename fields sice new extension can be generated by client and server.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3015)
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 1c98b53..698c25b 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -2041,7 +2041,7 @@
             rv |= CERT_PKEY_CERT_TYPE;
         }
 
-        ca_dn = s->s3->tmp.ca_names;
+        ca_dn = s->s3->tmp.peer_ca_names;
 
         if (!sk_X509_NAME_num(ca_dn))
             rv |= CERT_PKEY_ISSUER_NAME;