Reuse conversation cache when streaming edits (#30245)

Release Notes:

- Improved latency when the agent applies edits.

crates/assistant_tools/src/fetch_tool.rs

@@ -9,7 +9,7 @@ use futures::AsyncReadExt as _;
 use gpui::{AnyWindowHandle, App, AppContext as _, Entity, Task};
 use html_to_markdown::{TagHandler, convert_html_to_markdown, markdown};
 use http_client::{AsyncBody, HttpClientWithUrl};
-use language_model::{LanguageModel, LanguageModelRequestMessage, LanguageModelToolSchemaFormat};
+use language_model::{LanguageModel, LanguageModelRequest, LanguageModelToolSchemaFormat};
 use project::Project;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
@@ -142,7 +142,7 @@ impl Tool for FetchTool {
     fn run(
         self: Arc<Self>,
         input: serde_json::Value,
-        _messages: &[LanguageModelRequestMessage],
+        _request: Arc<LanguageModelRequest>,
         _project: Entity<Project>,
         _action_log: Entity<ActionLog>,
         _model: Arc<dyn LanguageModel>,