layout: Move text decoration propagation to stacking context tree construction (#37069)

Text decorations have a special kind of propagation. Instead of
propating these during box tree construction, move propagation to
stacking context tree construction. This will allow for using a very
easy type of incremental layout when text decorations change. For
instance, when a link changes color during hovering over it, we can skip
all of box and fragment tree construction.

In addition, propagation works a bit better now and color and style
properly move down from their originating `Fragment`s.

This introduces three new failures, because now we are drawing the
text-decoration with the correct color in more places, which exposes an
issue we have with text-decorations not being drawn in relation to the
baseline (taking into account `vertical-align`).

Testing: There are tests for these changes.
Fixes #31736.

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

tests/wpt/meta/css/css-text-decor/text-decoration-decorating-box-001.html.ini

@@ -0,0 +1,2 @@
+[text-decoration-decorating-box-001.html]
+  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-decoration-dotted-002.html.ini

@@ -1,2 +0,0 @@
-[text-decoration-dotted-002.html]
-  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-decoration-propagation-display-contents.html.ini

@@ -1,2 +0,0 @@
-[text-decoration-propagation-display-contents.html]
-  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-decoration-style-multiple.html.ini

@@ -1,2 +0,0 @@
-[text-decoration-style-multiple.html]
-  expected: FAIL

tests/wpt/meta/css/css-text-decor/text-shadow/decorations-multiple-zorder.html.ini

@@ -1,2 +0,0 @@
-[decorations-multiple-zorder.html]
-  expected: FAIL