The hit-testing position is now shifted by the scroll offsets before
performing any checks for containment. This is implemented by assigning
each PaintableBox/InlinePaintable an offset corresponding to the scroll
frame in which it is contained. The non-scroll-adjusted position is
still passed down when recursing to children because the assigned
offset accumulated for nested scroll frames.
With this change, hit testing works in the Inspector.
Fixes https://github.com/SerenityOS/serenity/issues/22068
