Feat: add status icon to session details header in side panel

What does this MR do and why?

This MR adds a status icon to the sessions header for the details view in the side panel.

References

GitLab Issue: #578708

Screenshots or screen recordings

Before	After

How to set up and validate locally

For DAP Setup

• General DAP: https://docs.gitlab.com/development/duo_agent_platform/
• Assigning Duo to a group: https://docs.gitlab.com/development/ai_features/#run-gitlabduosetup-script

To Test in Duo Side Rail (only test if regression testing this mode)

1. Turn on the following feature flags: duo_workflow, duo_workflow_in_ci, ai_flow_triggers and duo_side_rail.
2. Make sure you are NOT in the new UI
3. Open Duo Chat and open the Sessions tab (the two overlapping squares icon).
4. Test search queries (see below for test cases)
5. If you see no Sessions then run the following query bundle exec rake "gitlab:duo_workflow:populate[50,20,1,<<YOUR_TEST_GROUP_PATH_HERE>>]" to create new agent sessions. Refresh the page.
6. Test details view (see below for test cases)

To Test in Agent Sessions page

1. Navigate to a project with that has AI features enabled.
2. In the left side panel, you will see Automate with a tanuki icon. Select Sessions from the dropdown.
3. Test details view (see below for test cases)

To Test in new UI Side Panel

1. To test this locally, make sure you have the following FFs enabled: paneled_view, global_topbar, tailwind_container_queriesAfter you can toggle New UI on in user's setting under the user's profile dropdown
2. Open the side panel and open Sessions.
3. Test details view (see below for test cases)

Test Details View (The Actual Testing)

1. Go to the UI Side Panel, and select/click a Session item.
2. In the Session activity/details view, click the Details tab.
3. Validate the title now displays a status icon in the header.

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #578708