Windows gpui platform (#8490)

First implementation of gpui platform for Windows.

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/gpui/src/platform/windows/util.rs

@@ -0,0 +1,26 @@
+use windows::Win32::Foundation::{LPARAM, WPARAM};
+
+pub(crate) trait HiLoWord {
+    fn hiword(&self) -> u16;
+    fn loword(&self) -> u16;
+}
+
+impl HiLoWord for WPARAM {
+    fn hiword(&self) -> u16 {
+        ((self.0 >> 16) & 0xFFFF) as u16
+    }
+
+    fn loword(&self) -> u16 {
+        (self.0 & 0xFFFF) as u16
+    }
+}
+
+impl HiLoWord for LPARAM {
+    fn hiword(&self) -> u16 {
+        ((self.0 >> 16) & 0xFFFF) as u16
+    }
+
+    fn loword(&self) -> u16 {
+        (self.0 & 0xFFFF) as u16
+    }
+}