asn1: use ASN1_STRING accessors in crypto/cmp, crypto/ct, crypto/sm2, crypto/ts

asn1: use ASN1_STRING accessors in crypto/cmp, crypto/ct, crypto/sm2, crypto/ts

Replace direct ASN1_STRING struct member access (->data, ->length) with
public accessor functions ASN1_STRING_get0_data() and ASN1_STRING_length()
in consumer code across four subsystems.

Also fix i2d_SCT_LIST() in crypto/ct/ct_oct.c to heap-allocate
ASN1_OCTET_STRING via ASN1_OCTET_STRING_new() and ASN1_STRING_set0()
rather than stack-allocating it, since the struct is now opaque.

Removes #include <crypto/asn1.h> from all modified files except
crypto/cmp/cmp_protect.c, which retains it for ossl_X509_ALGOR_from_nid().

Reviewed-by: Matt Caswell <matt@openssl.foundation>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
MergeDate: Thu Mar 12 08:53:50 2026
(Merged from https://github.com/openssl/openssl/pull/30223)