Add Batch tool call for calling multiple tools (#27621)

<img width="620" alt="Screenshot 2025-03-27 at 2 29 13 PM"
src="https://github.com/user-attachments/assets/dd023507-61bc-4722-a095-f65f4b6c746a"
/>

We'll iterate on the UI, but first the goal is to just get it to work at
all so we can see if it's useful in terms of getting correct output
faster.

Release Notes:

- N/A

---------

Co-authored-by: Agus Zubiaga <hi@aguz.me>

crates/assistant_tools/src/assistant_tools.rs

@@ -1,4 +1,5 @@
 mod bash_tool;
+mod batch_tool;
 mod copy_path_tool;
 mod create_directory_tool;
 mod create_file_tool;
@@ -26,6 +27,7 @@ use http_client::HttpClientWithUrl;
 use move_path_tool::MovePathTool;
 
 use crate::bash_tool::BashTool;
+use crate::batch_tool::BatchTool;
 use crate::create_directory_tool::CreateDirectoryTool;
 use crate::create_file_tool::CreateFileTool;
 use crate::delete_path_tool::DeletePathTool;
@@ -47,6 +49,7 @@ pub fn init(http_client: Arc<HttpClientWithUrl>, cx: &mut App) {
 
     let registry = ToolRegistry::global(cx);
     registry.register_tool(BashTool);
+    registry.register_tool(BatchTool);
     registry.register_tool(CreateDirectoryTool);
     registry.register_tool(CreateFileTool);
     registry.register_tool(CopyPathTool);