Add an artifacts feature

[tarasglek]

• Using the new html support, we can modify our instructions to output code within a single code block within
  tag. We can that detect it and for example only show the code once like claude does...or show it to the right of the reasoning like claude does.
• Or connect the artifacts feature to edit a file over webrtc
• We could also use artifacts to speed up output of code edits via https://platform.openai.com/docs/guides/predicted-outputs (https://simonwillison.net/2024/Nov/4/predicted-outputs/#atom-everything is a better explanation)