Extend crypto plugin to support more key types

This change is part of "api-orders-add-more-types" BP phase 1 plan.
As per phase 1 we will extend the order resource to support asymmetric
and more symmetric keys.
This specific change is to address the crypto plug-in and extension
manager.

Partial-BP: api-orders-add-more-types

Change-Id: Idf0073c0703dff652e55e811538f86a8f7c7259b