gpui: Improve window.prompt to support ESC with non-English cancel text on macOS (#29538)

Release Notes:

- N/A

----

The before version GPUI used `Cancel` for cancel text, if we use
non-English text (e.g.: "取消" in Chinese), then the press `Esc` to cancel
will not work.

So this PR to change it by use `PromptButton` to instead the `&str`,
then we can use `PromptButton::cancel("取消")` for the `Cancel` button.

Run `cargo run -p gpui --example window` to test.

---

Platform Test:

- [x] macOS
- [x] Windows
- [x] Linux (x11 and Wayland)

---------

Co-authored-by: Mikayla Maki <mikayla@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>

crates/gpui/examples/window.rs

@@ -1,6 +1,6 @@
 use gpui::{
-    App, Application, Bounds, Context, KeyBinding, SharedString, Timer, Window, WindowBounds,
-    WindowKind, WindowOptions, actions, div, prelude::*, px, rgb, size,
+    App, Application, Bounds, Context, KeyBinding, PromptButton, PromptLevel, SharedString, Timer,
+    Window, WindowBounds, WindowKind, WindowOptions, actions, div, prelude::*, px, rgb, size,
 };
 
 struct SubWindow {
@@ -169,6 +169,42 @@ impl Render for WindowDemo {
                 let content_size = window.bounds().size;
                 window.resize(size(content_size.height, content_size.width));
             }))
+            .child(button("Prompt", |window, cx| {
+                let answer = window.prompt(
+                    PromptLevel::Info,
+                    "Are you sure?",
+                    None,
+                    &["Ok", "Cancel"],
+                    cx,
+                );
+
+                cx.spawn(async move |_| {
+                    if answer.await.unwrap() == 0 {
+                        println!("You have clicked Ok");
+                    } else {
+                        println!("You have clicked Cancel");
+                    }
+                })
+                .detach();
+            }))
+            .child(button("Prompt (non-English)", |window, cx| {
+                let answer = window.prompt(
+                    PromptLevel::Info,
+                    "Are you sure?",
+                    None,
+                    &[PromptButton::ok("确定"), PromptButton::cancel("取消")],
+                    cx,
+                );
+
+                cx.spawn(async move |_| {
+                    if answer.await.unwrap() == 0 {
+                        println!("You have clicked Ok");
+                    } else {
+                        println!("You have clicked Cancel");
+                    }
+                })
+                .detach();
+            }))
     }
 }
 
@@ -195,6 +231,7 @@ fn main() {
             },
         )
         .unwrap();
+
         cx.activate(true);
         cx.on_action(|_: &Quit, cx| cx.quit());
         cx.bind_keys([KeyBinding::new("cmd-q", Quit, None)]);