Consolidate Navigation Items into Tabs on Related Pages

## Job Story
When navigating within the Guardian, I want related items to be grouped together on a single page with tabs, so that the navigation menu can feel less busy, there are less places to visit and related items are grouped together.

Consolidate the number of items by grouping related fields into tabs. Here are some suggestions.

## Acceptance Criteria
- [ ] review menu items such as user management and system status
- [ ] group related items into page tabs
- [ ] review page routes

## Artifacts & Considerations
- see also #6538
- User Management —> Two sub tabs for: Users | Roles
- System Status —> Three sub tabs: Services | Logs | Worker Tasks
- Consider updating the routes so that its possible to bookmark an individual tab e.g. guardian-host/admin/user-management/users (or refactor into another task to update across the app for consistency)

Start by reviewing the Guardian menu items and page routes for User Management and System Status, and read the related context in #6538. Done means related items are grouped into the specified tabs, the navigation is less busy, and routes support bookmarking an individual tab or that route work is split into a follow-up task.

Written by the indexing model from the issue text.