Do not list PWAs in Spaces

[codedread]

Spaces currently shows all open chrome windows, even if those windows are Progressive Web Apps (with their own icon and identity on the user's operating system). For example, you can "install" Google Calendar as a PWA.

I am arguing that Spaces should not show these PWA windows in the Spaces window at all because they have no address bar and do not look like browser windows. Another reason is if you try to name a PWA as a Space:

• when you close and then try to open the PWA again through the OS, Spaces does not recognize the window as the previously named Space.
• when you close and then try to open the PWA again through the Spaces window, Spaces will simply open it as a browser window (and not as a PWA).

[codedread]

We need to experiment here. There is a type field on the Window object returned by chrome.windows.getCurrent(), etc.

https://developer.chrome.com/docs/extensions/reference/api/windows#type-WindowType suggests that type=app is deprecated. We need to understand what a PWA looks like to the Chrome extension APIs and whether we can even determine this.