LibWeb: Fix invalidation of CSS properties that do not affect layout

Recently, we moved the resolution of CSS properties that do not affect
layout to occur within LayoutState::commit(). This decision was a
mistake as it breaks invalidation. With this change, we now re-resolve
all properties that do not affect layout before each repaint.

Userland/Libraries/LibWeb/HTML/Navigable.h

@@ -179,6 +179,8 @@ public:
     };
     void paint(Painting::RecordingPainter&, PaintConfig);
 
+    void set_needs_to_resolve_paint_only_properties() { m_needs_to_resolve_paint_only_properties = true; }
+
 protected:
     Navigable();
 
@@ -220,6 +222,8 @@ private:
 
     CSSPixelSize m_size;
     CSSPixelPoint m_viewport_scroll_offset;
+
+    bool m_needs_to_resolve_paint_only_properties { true };
 };
 
 HashTable<Navigable*>& all_navigables();