Fix PKINIT cert matching data construction

Rewrite X509_NAME_oneline_ex() and its call sites to use dynamic
allocation and to perform proper error checking.

ticket: 8617
target_version: 1.16
target_version: 1.15-next
target_version: 1.14-next
tags: pullup
static void compat_dh_get0_pqg(const DH *dh, const BIGNUM **p,
                               const BIGNUM **q, const BIGNUM **g)
{
    if (p != NULL)
        *p = dh->p;
    if (q != NULL)
        *q = dh->q;
    if (g != NULL)
        *g = dh->g;
}

static void compat_dh_get0_pqg(const DH *dh, const BIGNUM **p,
                               const BIGNUM **q, const BIGNUM **g)
{
    if (p != NULL)
        *p = dh->p;
    if (q != NULL)
        *q = dh->q;
    if (g != NULL)
        *g = dh->g;
}
