STORE: Use the 'expect' param to limit the amount of decoders used

STORE: Use the 'expect' param to limit the amount of decoders used

In the provider file: scheme loader implementation, the OSSL_DECODER_CTX
was set up with all sorts of implementations, even if the caller has
declared a limited expectation on what should be loaded, which means
that even though a certificate is expected, all the diverse decoders
to produce an EVP_PKEY are added to the decoding change.

This optimization looks more closely at the expected type, and only
adds the EVP_PKEY related decoder implementations to the chain if
there is no expectation, or if the expectation is one of
OSSL_STORE_INFO_PARAMS, OSSL_STORE_INFO_PUBKEY, OSSL_STORE_INFO_PKEY.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15066)