Adding multi chats panel in @jupyter/chat package

[nakul-py]

Adding multi chats pannel to @jypyter/chat package and removing it from jyputerlab-chat. Now it can be easily imported and usable in juputerlab-chat and jupyterlite/ai.

• Closes Add a multi chats side panel in @jupyter/chat package #261

[github-actions]

👈 Launch a Binder on branch nakul-py/jupyter-chat/multichatpanel

[brichet]

Thanks @nakul-py for working on this.

I feel like this PR is not ready for review yet (e.g. we should not need the content manager in that chat, IMO).
Don't you think it should be converted to draft?

FYI I added some thoughts about this change in the issues.

[nakul-py]

@brichet These things have done:

• Defined ready promise in the AbstractChatModel.
• Defined IInputToolbarRegistry in @jupyter/chat.
• Added the Rename chat button.

Will you Test it now and suggest some improvements?

[brichet]

Thanks @nakul-py for updating it.
FYI I won't be able to review it until September.

[nakul-py]

Thanks @nakul-py for updating it. FYI I won't be able to review it until September.

Ok @brichet i am waiting...