Should the Chat trait take &mut Vec<Message> instead of Vec<Message> #1556

#[allow(refining_impl_trait)]
impl<M, P> Chat for Agent<M, P>
where
    M: CompletionModel,
    P: PromptHook<M> + 'static,
{
    #[tracing::instrument(skip(self, prompt, chat_history), fields(agent_name = self.name()))]
    async fn chat(
        &self,
        prompt: impl Into<Message> + WasmCompatSend,
        mut chat_history: Vec<Message>,
    ) -> Result<String, PromptError> {
        PromptRequest::from_agent(self, prompt)
            .with_history(&mut chat_history)
            .await
    }
}