BUG/MEDIUM: ssl: support SCTL with AWS-LC

BUG/MEDIUM: ssl: support SCTL with AWS-LC

AWS-LC owns extension 18 and rejects server custom extension registration.
The previous commit skips that registration, leaving .sctl files ignored.

Use SSL_CTX_set_signed_cert_timestamp_list(), available in all AWS-LC
releases, to set the serialized SCT list. AWS-LC copies the list and handles
context switches. Enable HAVE_SSL_SCTL for AWS-LC despite its missing
SN_ct_cert_scts OID.

AWS-LC also validates the list. Report a rejected list as a warning and omit
the extension, allowing the certificate to remain usable.

Tested with AWS-LC 4.2.0 and 3.0.0: TLS 1.2 sends the exact SCT payload for
the selected certificate with a sidecar and omits it for another certificate
on the same bind.

This must be backported to 3.0, the first version supporting AWS-LC.