wayland: Fix window state issues (#13885)

Fixes some issues with the CSD added in
https://github.com/zed-industries/zed/pull/13611

Here's a video comparing the master branch (yellow icon) with this PR
(blue icon):


https://github.com/zed-industries/zed/assets/71973804/35be443a-8f24-4aed-910b-625bad9821e2

_Note: the flicker at the bottom of the window when maximizing is an
issue with the KDE floating task bar, it happens with all programs._

Release Notes:

- N/A

crates/gpui/src/platform.rs

@@ -281,6 +281,16 @@ pub struct Tiling {
 }
 
 impl Tiling {
+    /// Initializes a [`Tiling`] type with all sides tiled
+    pub fn tiled() -> Self {
+        Self {
+            top: true,
+            left: true,
+            right: true,
+            bottom: true,
+        }
+    }
+
     /// Whether any edge is tiled
     pub fn is_tiled(&self) -> bool {
         self.top || self.left || self.right || self.bottom