Notes

• The "Users" sidebar item currently just directs you to the existing /users route.
• Ensure that groups can still be modified for single-org deployments. (We've been exposing groups as a top-level resource, but they're actually org scoped, so we need to make sure these settings stay accessible)
• Don't show organization settings for single-org deployments. All users should be added as members of the single-org transparently, and the org-level auditing page would just show all the same things as the global one.
• Groups should be shown as a "Deployment" setting rather than under an org, until there is more than one org.

Goals

• Change the /users route to /deployment/users, and add a<Redirect> to avoid breaking links.
• Make sure that the page integrates with/looks good in the new context (eg. the correct sidebar item is highlighted).
• Remove the Users/Groups tab bar from the top of the Users page
• Add a "Groups" sidebar item underneath the Deployment settings for single-org deployments.
• Add a /deployment/groups route that behaves the same as /organizations/default/groups, and redirects if there is more than one org.