Add a setting to show time to first window draw and frames per second in status bar (#16422)

I want to showcase Zed's performance via videos, and this seemed like a
good way to demonstrate it.


https://github.com/user-attachments/assets/f4a5fabc-efe7-4b48-9ba5-719882fdc856

Release Notes:

- On macOS, you can now set assign `performance.show_in_status_bar:
true` in your settings to show the time to the first window draw on
startup and then current FPS of the containing window's renderer.

---------

Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
Co-authored-by: Kirill Bulatov <kirill@zed.dev>
Co-authored-by: David Soria Parra <167242713+dsp-ant@users.noreply.github.com>
Co-authored-by: Danny Hua <danny.hua@hey.com>

crates/workspace/src/workspace.rs

@@ -38,7 +38,7 @@ use gpui::{
     ResizeEdge, Size, Stateful, Subscription, Task, Tiling, View, WeakView, WindowBounds,
     WindowHandle, WindowId, WindowOptions,
 };
-use item::{
+pub use item::{
     FollowableItem, FollowableItemHandle, Item, ItemHandle, ItemSettings, PreviewTabsSettings,
     ProjectItem, SerializableItem, SerializableItemHandle, WeakItemHandle,
 };