Collapsible navigation and page breadcrumbs added

We've made some minor updates to navigation in the app.

• Left navigation column can now be collapsed to an icon-only view to allow more space for page content
• Mobile navigation uses the same UI in a slide out drawer
• Pages now have breadcrumb links next to the new side navigation toggle icon
• Pages that are branch-specific now show the branch picker to the right of the breadcrumbs for improved consistency