"Open Folder" button label in path popover could be clearer

While running into issue #260 (closed), I was quite confused by the "Open Folder" button shown here:

The "Open Folder" button is actually something to open the path with Nautilus, instead of opening the filechooser to change the path... which is actually the tiny folder icon button above the popover.

I would suggest to rename that "Open Folder" button to something unambiguous, like "View in File Manager", so that it's clear it's not the button to pick a replacement path. If you find that label too long and want to keep it as short as possible, it could be "View folder", and make the GtkTooltip for it much more verbose (since just two words isn't a lot for users to figure out what this is before clicking).