Add to support open Popover as a child window.

[huacnlee]

Goal

Change to let Popup elements open into a window, to make sure the Popup windows, panels, menus render top than the WebView.

Then we can embed wry or other webview into GPUI.

CleanShot.2024-07-11.at.11.53.16.mp4

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This is also like other software, they are also used in child window to render the menus, popups.

• Add WebView #2
• gpui: Export raw_window_handle for wry to render WebView, and with a WebView example zed-industries/zed#13730

Todos

• Multiple display window position.
• Windows transparent background. (No transparent, just render a correct window border)
• Disable window resize on Windows.
• Handle Menu action.
• Provided popover or window two mode to uses.

[huacnlee]

CleanShot.2024-07-09.at.20.45.22.mp4

[huacnlee]

2024-07-09.211919.mp4

On Windows, now the Popover position is right, but the window size not correct.

[huacnlee]

2024-07-09.213837.mp4