Integrate custom window frames for each desktop platform

[Keavon]

The Graphite editor UI includes its own window header bar frame, so we need to disable the native window frame and allow dragging the title bar and resizing the window corners. This is similar to what VS Code does.

Here's an article on/related to the topic for Windows: https://learn.microsoft.com/en-us/windows/win32/dwm/customframe It is important to take an approach on Windows which does not break Aero Snap.

This has to happen for Windows, Mac, and Linux, and we need to enable each platform-specific custom platform title bar that we have a separate Svelte component for (#3078). Mac will need to temporarily have the menu bar brought back beside its left-aligned window control buttons, until we can eventually use native APIs to replicate that functionality in the OS menu bar.