Prevent newly focused windows to steal focus from Shell (Take 3)
Segue from !2832 (merged) and !2776 (merged).
Revert the previous remaining commits and try a 3rd approach, namely:
- _NET_ACTIVE_WINDOW from clients is ignored while GNOME Shell has focus
- The implicit focus during
meta_window_show()
is avoided in the same situation
This seems to address the original gnome-shell#5932 (closed) more specifically, while avoiding other situations where mutter is actually switching focus between already visible windows while holding a grab for legit reasons, like alt-tab.