CE-1847: use common GlobalAppBar

• Replaces custom GlobalAppBar with nav menu using the common-ui component
• Replaces the user login/logout buttons (uses common context and components, and retains the redirect to /login when accessing unauthorized resources)
• does NOT add the "create ioc button" to the global app bar (tbd in CE-426)
• removes unused getUser method from user context
• ensures page and app title is set, adds a breadcrumb utility function

Closes CE-1847