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/interactive.rs

@@ -436,6 +436,7 @@ impl PlatformInput {
 
 #[cfg(test)]
 mod test {
+
     use crate::{
         self as gpui, div, Element, FocusHandle, InteractiveElement, IntoElement, KeyBinding,
         Keystroke, ParentElement, Render, TestAppContext, VisualContext,