[FEATURE] Clear/rewrite buttons in chat

[alejandro5042]

Please consider adding a "Clear" button to the chat, so you can begin again; and/or a "Rewrite" button that puts the latest user message in the chat box again so you can try a variant.

[nmetulev]

I think this is a great idea - we can add this to the backlog. Feel free to also submit a PR if this is something you want to do, just let me know.

[haoliuu]

Feature change merged #431. Should be included in next 0.5.1 release.