Update the tls13encryptiontest for new read record layer

Update the tls13encryptiontest for new read record layer

The tls13encryption is an internal test that reaches inside libssl
to test encryption/decryption of records. It needs to be amended for the
new code structure so that it is testing the equivalent things as before.

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18132)