linux: Fix IME panel position while enumerating input methods (#12495)

Release Notes:

- N/A

This updates the IME position every time the selection changes, this is
probably only useful when you enumerate languages with your IME.

TODO:
- ~There is a rare chance that the ime panel is not updated because the
window input handler is None.~
- ~Update IME panel in vim mode.~
- ~Update IME panel when leaving Buffer search input.~

---------

Co-authored-by: Mikayla Maki <mikayla@zed.dev>

crates/gpui/src/window.rs

@@ -3575,6 +3575,18 @@ impl<'a> WindowContext<'a> {
         self.window.platform_window.toggle_fullscreen();
     }
 
+    /// Updates the IME panel position suggestions for languages like japanese, chinese.
+    pub fn invalidate_character_coordinates(&mut self) {
+        self.on_next_frame(|cx| {
+            if let Some(mut input_handler) = cx.window.platform_window.take_input_handler() {
+                if let Some(bounds) = input_handler.selected_bounds(cx) {
+                    cx.window.platform_window.update_ime_position(bounds);
+                }
+                cx.window.platform_window.set_input_handler(input_handler);
+            }
+        });
+    }
+
     /// Present a platform dialog.
     /// The provided message will be presented, along with buttons for each answer.
     /// When a button is clicked, the returned Receiver will receive the index of the clicked button.