Inline nodes in our layout tree have a position, so let's show it. By
centralizing the logic for this, block nodes now lose their redundant
'content-size' dump info which is already part of the box model dump.
This patch just adds the new root paintable and updates the tests
expectations. The next patch will move painting logic from the layout
viewport to the paint viewport.
Using avilable space directly while resolving table container width
allows to avoid assigning it to table wrapper box content width which
sometimes involves infinite (saturated) values.
Also this allows to get rid of set_max_content_width() which is a hack
that allows to bypass set_content_width() to assign infinite
(saturated) width to a box.
Closes https://github.com/SerenityOS/serenity/issues/19521
