A fuller implementation of PARAMS_TEMPLATE as per #9266 but renamed.
This introduces a statis data type which can be used to constructor a
description of a parameter array. It can then be converted into a OSSL_PARAM
array and the allocated storage freed by a single call to OPENSSL_free.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9305)
