Streaming tool calls (#29179)

https://github.com/user-attachments/assets/7854a737-ef83-414c-b397-45122e4f32e8



Release Notes:

- Create file and edit file tools now stream their tool descriptions, so
you can see what they're doing sooner.

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/language_model/src/language_model.rs

@@ -187,6 +187,7 @@ pub struct LanguageModelToolUse {
     pub id: LanguageModelToolUseId,
     pub name: Arc<str>,
     pub input: serde_json::Value,
+    pub is_input_complete: bool,
 }
 
 pub struct LanguageModelTextStream {