When a parent element's display property changes (e.g., to flex or
grid), children may need to be blockified or un-blockified.
Previously, children only received a recompute_inherited_style() call
which doesn't run the blockification logic.
This patch adds a parent_display_changed flag to the recursive style
update that forces children to get a full style recompute when their
parent's display change triggers a layout tree rebuild.
This allows us to disable test output, which performs expensive assert
tracking. This was making our imported tests run significantly slower
than tests run via `WPT.sh`.
Formatting the output ourselves also allows us to remove unnecessary
information from the test output.
This commit also rebaselines all existing imported WPT tests to follow
the new format.