Add new public API for checking certificate times.

Add new public API for checking certificate times.

Fixes: #1631
This changes the previously internal ossl_x509_check_certificate_times()
to be the public X509_check_certificate_times(). It adds documentation
for the new function and marks X509_cmp_time, X509_cmp_timeframe,
and X509_cmp_current_time as deprecated in 4.0, as discussed in #1631.

Since the function is now public, we can replace the remaining
uses of deprecated stuff with this function.

Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/29152)