Search open windows

When I search for "Files" and already have an open instance of Files, search could suggest to focus the open instance (focus meaning switching to the workspace and bringing the window to the front), additionally to opening a new instance.

The inspiration for this comes from the "awesome bar" in Firefox, which suggests already open tabs when you type an URL. Selecting the already open tab will close the current tab if it's empty and switch to the already existing tab.

This is useful to search in all the things you have open and avoids opening something like Files again, when you already have it open somewhere that you aren't using.