Add SSL_CTX_use_cert_and_key (#2163)

### Issues:
`CryptoAlg-2863`

### Description of changes: 
Adds the function SSL_CTX_use_cert_and_key which sets the leaf, chain,
and private key all in one operation. This function is also needed by
librdkafka.

### Call-outs:
Point out areas that need special attention or support during the review
process. Discuss architecture or design changes.

### Testing:
Tests using this API to set the relevant fields and ensure TLS
connection succeeds.

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license and the ISC license.

---------

Co-authored-by: Justin W Smith <[email protected]>
Co-authored-by: Justin Smith <[email protected]>

Author: smittals2

crypto/err/ssl.errordata

@@ -112,6 +112,7 @@ SSL,308,NEGOTIATED_ALPS_WITHOUT_ALPN
 SSL,170,NEGOTIATED_BOTH_NPN_AND_ALPN
 SSL,285,NEGOTIATED_TB_WITHOUT_EMS_OR_RI
 SSL,171,NESTED_GROUP
+SSL,323,NOT_REPLACING_CERTIFICATE
 SSL,307,NO_APPLICATION_PROTOCOL
 SSL,172,NO_CERTIFICATES_RETURNED
 SSL,173,NO_CERTIFICATE_ASSIGNED