Configurable introspection data storage backend [1] is proposed
to provide flexible extension of introspection data storage
instead of the single support of Swift storage backend.
This patch adds plugin mechanism for loading introspection
storage, creates database backend and moves Swift storage
into a plugin.
[1] http://specs.openstack.org/openstack/ironic-inspector-specs/specs/configurable-introspection-data-backends.html
Story: 1726713
Task: 11373
Co-Authored-By: Kaifeng Wang <kaifeng.w@gmail.com>
Change-Id: Ie4d09dc0afc441b20a1e5e3bd8e742b1df918954