Add v1 Drag and Drop Team Composition to AGS

[victordibia]

This PR extends AGS with the following

• Refactor playground/sessions to add a hidable sidebar with a list of sessions for easy switching across sessions
• Adds a dedicated page for teams
  • Enables switching between modifying raw JSON config for teams and
  • Visual drag and drop view that enables users drag in items from a Component gallery to an agent

https://github.com/user-attachments/assets/4b398f11-1035-464c-abcb-2af22eb0fe24

Fairly large PR, which will be improved over time (e.g., adding support for 3rd party agent teams #4203 )

Why are these changes needed?

Related issue number

Closes #4202

Checks

• [ ] I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• [ ] I've added tests (if relevant) corresponding to the changes introduced in this PR.
• [ ] I've made sure all auto checks have passed.