shell/app: Adapt to focus changes in mutter

meta_window_raise_and_make_recent() now only works as advertised for windows on the active workspace.

That results in the following unexpected behavior:

1. open two windows of an app (say: terminal)
2. open another app, maximize the window for best effect
3. switch to another workspace
4. super+tab to the first app: both windows are raised
5. close the window; instead of moving focus to the 2nd app window, both windows disappear because focus is moved to the app from 2

This works around the issue, although I'd argue that the issue is in the current mutter behavior.