LibWeb: Cache intrinsic sizes across layout runs

This change moves intrinsic sizes cache from
LayoutState, which is local to current layout run,
to layout nodes, so it could be reused between
layout runs. This optimization is possible because
we can guarantee that these measurements will
remain unchanged unless the style of the element
or any of its descendants changes.

For now, invalidation is implemented simply by
resetting cache on whole ancestors chain once we
figured that element needs layout update.
The case when layout is invalidated by DOM's
structural changes is covered by layout tree
invalidation that drops intrinsic sizes cache
along with layout nodes.

I measured improvement on couple websites:
- Mail list on GMail 28ms -> 6ms
- GitHub large code page 47ms -> 36ms
- Discord chat history 15ms -> 8ms
(Time does not include `commit()`)

Libraries/LibWeb/DOM/Document.h

@@ -50,26 +50,6 @@ enum class QuirksMode {
     Yes
 };
 
-#define ENUMERATE_SET_NEEDS_LAYOUT_REASONS(X)         \
-    X(CharacterDataReplaceData)                       \
-    X(FinalizeACrossDocumentNavigation)               \
-    X(HTMLImageElementReactToChangesInTheEnvironment) \
-    X(HTMLImageElementUpdateTheImageData)             \
-    X(HTMLVideoElementSetVideoTrack)                  \
-    X(KeyframeEffect)                                 \
-    X(LayoutTreeUpdate)                               \
-    X(NavigableSetViewportSize)                       \
-    X(SVGImageElementFetchTheDocument)                \
-    X(StyleChange)
-
-enum class SetNeedsLayoutReason {
-#define ENUMERATE_SET_NEEDS_LAYOUT_REASON(e) e,
-    ENUMERATE_SET_NEEDS_LAYOUT_REASONS(ENUMERATE_SET_NEEDS_LAYOUT_REASON)
-#undef ENUMERATE_SET_NEEDS_LAYOUT_REASON
-};
-
-[[nodiscard]] StringView to_string(SetNeedsLayoutReason);
-
 #define ENUMERATE_INVALIDATE_LAYOUT_TREE_REASONS(X)       \
     X(DocumentAddAnElementToTheTopLayer)                  \
     X(DocumentRequestAnElementToBeRemovedFromTheTopLayer) \
@@ -358,8 +338,6 @@ public:
     void update_paint_and_hit_testing_properties_if_needed();
     void update_animated_style_if_needed();
 
-    void set_needs_layout(SetNeedsLayoutReason);
-
     void invalidate_layout_tree(InvalidateLayoutTreeReason);
     void invalidate_stacking_context_tree();
 
@@ -1076,8 +1054,6 @@ private:
     // Used by evaluate_media_queries_and_report_changes().
     Vector<WeakPtr<CSS::MediaQueryList>> m_media_query_lists;
 
-    bool m_needs_layout { false };
-
     bool m_needs_full_style_update { false };
     bool m_needs_full_layout_tree_update { false };