Function indy_sys::anoncreds::indy_prover_search_credentials_for_proof_req

#[no_mangle]
pub unsafe extern "C" fn indy_prover_search_credentials_for_proof_req(
    command_handle: Handle, 
    wallet_handle: Handle, 
    proof_request_json: CString, 
    extra_query_json: CString, 
    cb: Option<ResponseI32CB>
) -> Error