Add a way to cleanse params arrays

Add a way to cleanse params arrays

This uses the return_size field of the last terminating parameter
similaraly to how secure memory uses the data and data_size fields,
to hold the total size of memory allocated for params.
This is then used to be able to call OPENSSL_cleanse on the params
fields via the new OSSL_PARAM_clear_free() call.

Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/28108)