TEST: Modify test/recipes/90-test_store.t for use with different 'file:' loaders

TEST: Modify test/recipes/90-test_store.t for use with different 'file:' loaders

We want to perform the same tests with a provider implementation, and
also make sure that an ENGINE implementation works as advertised.

OSSL_STORE_open() / OSSL_STORE_open_wirh_libctx() work in such a way
that they look for internal / engine implementations first, and only
failing that, they will try to fetch a provider implementation.  This
ensures that when we do specify an engine, it gets exceptional priority.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/12587)