Popup style is off on wayland

[gudvinr]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.101.1
• OS Version: Arch Linux

Steps to Reproduce:

1. Open any popup window ("Help: About", etc)

You see that all corners are not rounded. Title font is black on dark background.

Compare this to Dolphin About view:

From what I see, issue only happens with "window.titleBarStyle": "custom" which is the default. But with "window.titleBarStyle": "custom" you'll enormous menus (I guess that's #224515).

That ultimately means vscode will be broken on Wayland one way or another.