Fix bug with IME

Adjust how IME works in the terminal

co-authored-by: nathan <nathan@zed.dev>

crates/gpui2/src/platform.rs

@@ -145,6 +145,7 @@ pub trait PlatformWindow {
     fn mouse_position(&self) -> Point<Pixels>;
     fn as_any_mut(&mut self) -> &mut dyn Any;
     fn set_input_handler(&mut self, input_handler: Box<dyn PlatformInputHandler>);
+    fn clear_input_handler(&mut self);
     fn prompt(&self, level: PromptLevel, msg: &str, answers: &[&str]) -> oneshot::Receiver<usize>;
     fn activate(&self);
     fn set_title(&mut self, title: &str);