feat: Complete chat history panel integration

[john-carroll-sw]

• Added chat history functionality to display transcriptions from both model responses and user inputs.
• Modified App.tsx, types.ts, and history-panel.tsx to support the history panel logic.
• Updated translation.json for localized strings related to the chat history.

This update enhances the user experience by providing a comprehensive view of the conversation history.

[john-carroll-sw]

The screenshot is slightly misleading. The changes I am committing are only for the history panel pieces. I have not committed any UI changes that are for my demo around Starbucks AI Assistant. Apologies for the confusion in advance. I wanted to show the grounding files in the assistant's chat bubbles and this was my only working demo at the moment.

[john-carroll-sw]

This is what the UI looks like. Open to suggestions on how the chat history can be shown. Right now it's the blue button in the middle.

[chuwik]

Thanks for the PR!

I'd render the 'Show Chat History' button in a smaller one, e.g.

<Button variant="outline" size="sm" className="rounded-full">
    <History className="mr-2 h-4 w-4" />
    Show history
</Button>

[john-carroll-sw]

Current UI showing transcript history panel:

[pmuralikrishna111]

this is nice feature. i wanted to pull it upon merged.