Fix #5532: return user to Admin Search after Make Non-Discoverable flow

[guillermo-escire]

References

Fixes #5532

Description

When clicking Cancel or Make Non-Discoverable in the Make Non-Discoverable flow,
the user was being redirected to the item's administer page instead of returning
to Admin Search. This fix returns the user to the previous page (Admin Search)
after completing or cancelling the action.

Instructions for Reviewers

List of changes in this PR:

• Modified abstract-simple-item-action.component.ts to capture the previous URL
• using router.lastSuccessfulNavigation and use it as the redirect destination
• after the action completes or fails.
• Modified abstract-simple-item-action.component.html to use navigateByUrl(returnUrl)
• on the Cancel button instead of a hardcoded routerLink to the item edit page.
• Updated abstract-simple-item-action.component.spec.ts to reflect the new
• navigation behavior.

Steps to test:

1. Go to Admin Search from the management sidebar.
2. Search for any item.
3. Click Make non-discoverable.
4. Click Cancel — you should be returned to Admin Search.
5. Repeat steps 1-3 and click Make it non-discoverable — you should also be returned to Admin Search.
6. Verify that accessing the Make Non-Discoverable page directly (not from Admin Search)
   still redirects to the item edit page after the action.

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