LibWeb: Express intrinsic size layout via size constraints

Previously, we had three layout modes:

- Normal:
    - Everything uses the computed values from CSS.

- MinContent:
    - Containing blocks act as if they have 0 width.
    - All line breaking opportunities are taken.

- MaxContent:
    - Containing blocks act as if they have infinite width.
    - Only forced line breaks are accepted.

The above was based on a set of misunderstandings of CSS sizing.
A major problem with the above was that *all* containing blocks
behaved differently during intrinsic size layout, not just the
relevant one.

With this patch there are only two layout modes:

- Normal:
    - Everything uses the computed values from CSS.

- IntrinsicSizeDetermination:
    - One or more boxes have size constraints applied.

There are two size constraints per layout box, set here:

- FormattingState::NodeState::width_constraint
- FormattingState::NodeState::height_constraint

They are of type SizeConstraint and can be one of None, MinContent,
or MaxContent. The default is None.

When performing an IntrinsicSizeDetermination layout, we now assign
a size constraint to the box we're trying to determine the intrinsic
size of, which is then honored by using two new helpers to query
the dimensions of containing blocks:

- FormattingContext::containing_block_width_for(Box)
- FormattingContext::containing_block_height_for(Box)

If there's a relevant constraint in effect on the Box, the size of
its containing block is adjusted accordingly.

This is essentially an implementation of the "available space"
constraints from CSS-SIZING-3. I'm sure some things will break from
this, and we'll have to deal with that separately.

Spec: https://drafts.csswg.org/css-sizing-3/#available

Userland/Libraries/LibWeb/Layout/TableFormattingContext.cpp

@@ -119,7 +119,13 @@ void TableFormattingContext::calculate_column_widths(Box const& row, CSS::Length
         auto const& computed_values = cell.computed_values();
         auto specified_width = computed_values.width().resolved(cell, table_width).resolved(cell);
 
-        compute_width(cell, specified_width.is_auto() ? LayoutMode::MinContent : LayoutMode::Normal);
+        if (specified_width.is_auto()) {
+            auto width = calculate_max_content_width(cell);
+            cell_state.content_width = width;
+        } else {
+            compute_width(cell, LayoutMode::Normal);
+        }
+
         (void)layout_inside(cell, LayoutMode::Normal);
 
         if (cell.colspan() == 1) {