Sketch in assistant edit button (#19705)

Add an edit button to the assistant. This is totally hacked in for now,
just to see how this would feel rendered simply in the UI.

![CleanShot 2024-10-24 at 16 26
14@2x](https://github.com/user-attachments/assets/e630d078-78b7-42d7-93f1-cf61c00bd20e)

cc @as-cii @danilo-leal 

Release Notes:

- N/A

---------

Co-authored-by: Danilo Leal <67129314+danilo-leal@users.noreply.github.com>
Co-authored-by: Richard Feldman <oss@rtfeldman.com>

crates/assistant/src/inline_assistant.rs

@@ -1,7 +1,7 @@
 use crate::{
     assistant_settings::AssistantSettings, humanize_token_count, prompts::PromptBuilder,
     AssistantPanel, AssistantPanelEvent, CharOperation, CycleNextInlineAssist,
-    CyclePreviousInlineAssist, LineDiff, LineOperation, ModelSelector, StreamingDiff,
+    CyclePreviousInlineAssist, LineDiff, LineOperation, ModelSelector, RequestType, StreamingDiff,
 };
 use anyhow::{anyhow, Context as _, Result};
 use client::{telemetry::Telemetry, ErrorExt};
@@ -2234,7 +2234,7 @@ impl InlineAssist {
                     .read(cx)
                     .active_context(cx)?
                     .read(cx)
-                    .to_completion_request(cx),
+                    .to_completion_request(RequestType::Chat, cx),
             )
         } else {
             None