Open new windows with a default size and position (#9204)

This PR changes GPUI to open windows with a default size and location,
and to otherwise inherit from their spawning window.

Note: The linux build now crashes on startup.

Release Notes:

- N/A

---------

Co-authored-by: Nathan <nathan@zed.dev>
Co-authored-by: Ezekiel Warren <zaucy@users.noreply.github.com>

crates/gpui/src/platform/mac/platform.rs

@@ -3,7 +3,7 @@ use crate::{
     Action, AnyWindowHandle, BackgroundExecutor, ClipboardItem, CursorStyle, DisplayId,
     ForegroundExecutor, Keymap, MacDispatcher, MacDisplay, MacTextSystem, MacWindow, Menu,
     MenuItem, PathPromptOptions, Platform, PlatformDisplay, PlatformInput, PlatformTextSystem,
-    PlatformWindow, Result, SemanticVersion, Task, WindowAppearance, WindowOptions,
+    PlatformWindow, Result, SemanticVersion, Task, WindowAppearance, WindowParams,
 };
 use anyhow::{anyhow, bail};
 use block::ConcreteBlock;
@@ -477,6 +477,10 @@ impl Platform for MacPlatform {
         }
     }
 
+    fn primary_display(&self) -> Option<Rc<dyn PlatformDisplay>> {
+        Some(Rc::new(MacDisplay::primary()))
+    }
+
     fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {
         MacDisplay::all()
             .map(|screen| Rc::new(screen) as Rc<_>)
@@ -494,7 +498,7 @@ impl Platform for MacPlatform {
     fn open_window(
         &self,
         handle: AnyWindowHandle,
-        options: WindowOptions,
+        options: WindowParams,
     ) -> Box<dyn PlatformWindow> {
         // Clippy thinks that this evaluates to `()`, for some reason.
         #[allow(clippy::unit_arg, clippy::clone_on_copy)]