Resolve "[FE] Add work item settings page in admin settings"

What does this MR do and why?

This change adds a new "Work item settings" page to the admin panel that is only available in the Enterprise Edition (EE) version of the application.

The update creates a new admin settings section where administrators can configure work item-related features.

1. The page is restricted to EE customers only - if someone tries to access it on the free version, they'll get a "not found" error.
2. The changes include adding the new page to the admin navigation menu, creating the actual settings page with proper titles and styling, and setting up the necessary routing so users can navigate to it.
3. The page follows the same pattern as other admin settings pages, allowing administrators to view and update work item configurations through a web interface.
4. If the FF work_item_configurable_types is switched off , the menu item is not added and the page gives 404

This is a part of adding settings page to work items types admin instance (to be used in organizations in future)

References

Screenshots or screen recordings

Use case	Menu item	Page
When the FF is off EE instance
When is FF is on EE instance
When the FF is off in CE instance
When the FF is on in CE instance

How to set up and validate locally

1. Enable the FF work_item_configurable_types
2. Go to admin instance
3. See that you can see the work item settings page
4. Switch off the FF and see that you cannot access the work item settings page
5. Make sure when you switch to FOSS ONLY mode , you are not able to access the page or see it in the menu

MR acceptance checklist

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Related to #581109