driver: Manually parse the direction from harfbuzz

Since [1], `setlocale()` was replaced with `uselocale()`. This
makes calling `gtk_get_locale_direction()` wrong as it relied on
the global, thread-unsafe locale, rather than the current thread
locale. In order to preserve thread safety, manually call the
needed functions from Pango and HarfBuzz. This will make the
direction change when changing languages.

Also see [2] for clarification on the function used internally
by `gtk_get_locale_direction()`.

[1] 83696b54
[2] https://gitlab.gnome.org/GNOME/pango/-/commit/15fe8555e5b859d1612bc8815aeb40c1832821ae

Part-of: <https://gitlab.gnome.org/GNOME/gnome-initial-setup/-/merge_requests/240>