No need to handle filterUnits specially anymore
No need to handle filterUnits specially anymore

It used to be that the x/y/width/height attributes were validated
based on the filterUnits attribute, but this was a mis-reading of the
spec.  So, just process filterUnits as a normal attribute.

Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/631>

GNOME/librsvg,GNOME/librsvg,GNOME/librsvg,GNOME/librsvg