Feat: Update Session List Item format

What does this MR do and why?

This MR updates the Session List Item format to match the latest Figma (see here) designs.

References

GitLab Work Item: #587231 (closed)

Screenshots or screen recordings

Before	After

How to set up and validate locally

For DAP/General 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
• Make sure you are in SaaS mode with export GITLAB_SIMULATE_SAAS=1 set in your env.runit file in your local gdk.
• Turn on the following feature flags: duo_workflow, duo_workflow_in_ci, ai_flow_triggers.

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 ai panel (see below for test cases)

Adding Sessions

1. A: If you see no Sessions, you can trigger one that displays a Pipeline/Job by going to an Issue within your Duo enabled project and clicking the Generate MR with Duo button. It should trigger a new session that you can open up.
2. B: You can also 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. Make sure the group you are testing in has Duo assigned (see DAP setup above).

Test Side Panel (The Actual Testing)

1. Go to the new Side Panel (see above for setup) and open Sessions
2. Validate the items follow the new format (see attached Issue/Work Item for design validation). If there is no session activity available, the last status message will display with the last updated value. Otherwise it should display the last status message and last updated value with a - in between.

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 #587231 (closed)