swipeTracker: Pass orientation in constructor

swipeTracker: Pass orientation in constructor

When this class was written, all swipes in the shell were vertical, so it
made sense to make the default orientation vertical. This isn't the case
anymore, thus pass make it mandatory to specify orientation when creating
a tracker.

Change the property default values to horizontal as well to match Clutter
instead of the old shell design.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1731>