layout: Initial implementation of flex-direction: column and column-reverse (#33031)

This change removes restrictions on using the column layout mode of
flexbox and adds an initial implementation of sizing for that flex
direction. There's a lot of missing pieces still, but in some cases this
does render column flexbox.

In particular, there are now two code paths for preferred widths
(intrinsic size) calcuation: one in the main axis (row) and one in
the cross axis (column) corresponding to the flex direciton with
horizontal writing modes.

In addition, `FlexItemBox::inline_content_sizes` is removed in favor of
making `sizing::outer_inline` /
`IndependentFormattingContext::outer_inline_content_sizes` generic
enough to handle using a different value for auto minimum sizes, which
flexbox needs.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>

components/layout_2020/flow/inline/mod.rs

@@ -2389,6 +2389,7 @@ impl<'a> ContentSizesComputation<'a> {
                 let outer = atomic.outer_inline_content_sizes(
                     self.layout_context,
                     self.containing_block_writing_mode,
+                    Au::zero,
                 );
 
                 if !inline_formatting_context