Set appid/wmclass for zed window (#10909)

fixes https://github.com/zed-industries/zed/issues/9132

By setting the app id, window managers like `sway` can apply custom
configuration like `for_window [app_id="zed"] floating enable`.
Tested using `wlprop`/`hyprctl activewindow` for wayland, `xprop` for
x11.


Release Notes:

- Zed now sets the window app id / class, which can be used e.g. in
window managers like `sway`/`i3` to define custom rules

crates/gpui/src/platform/linux/x11/window.rs

@@ -494,6 +494,21 @@ impl PlatformWindow for X11Window {
             .unwrap();
     }
 
+    fn set_app_id(&mut self, app_id: &str) {
+        let mut data = Vec::with_capacity(app_id.len() * 2 + 1);
+        data.extend(app_id.bytes()); // instance https://unix.stackexchange.com/a/494170
+        data.push(b'\0');
+        data.extend(app_id.bytes()); // class
+
+        self.0.xcb_connection.change_property8(
+            xproto::PropMode::REPLACE,
+            self.0.x_window,
+            xproto::AtomEnum::WM_CLASS,
+            xproto::AtomEnum::STRING,
+            &data,
+        );
+    }
+
     // todo(linux)
     fn set_edited(&mut self, edited: bool) {}