Feat: Update naming of Agent Sessions to Sessions

What does this MR do and why?

This MR updates the naming of Agent sessions to Sessions on the Project Sessions Page (breadcrumbs and page title), as well as updates the navigation order (and updates the name in the navigation).

References

Related Issue: #577713 (closed)

Screenshots or screen recordings

Before	After

How to set up and validate locally

To Test in Agent Sessions page

1. Turn on the following feature flags: duo_workflow, duo_workflow_in_ci, and ai_flow_triggers.
2. Navigate to a project with that has AI features enabled.
3. In the left side panel, you will see Automate with a tanuki icon. Select Sessions from the dropdown (also validate the new order as well as re-naming).
4. On the Sessions page validate the updated breadcrumbs and page title (the url will not be updated yet at this time).

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Closes #577713 (closed)