Add array memory allocation routines

Add array memory allocation routines

Such routines allow alleviating the need to perform explicit integer
overflow check during allocation size calculation and generally make
the allocations more semantic (as they signify that a collection
of NUM items, each occupying SIZE bytes is being allocated), which paves
the road for additional correctness checks in the future.

Signed-off-by: Eugene Syromiatnikov <esyr@openssl.org>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28059)