Move evp test programs input data to its own data dir

This is a manual backport of #3472 to 1.1.0.
This is a partial backport, limited only to evptests, as #3472 also
affected bntests, which has a completely different form in 1.1.0.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7152)