LibHTML: Rename Document::normalize() to fixup() and always do it

Node.normalize() is a standard DOM API that coalesces Text nodes.
To avoid clashing with that, rename it to fixup().

This patch also makes it happen automagically as part of parsing.

Libraries/LibHTML/DOM/Document.cpp

@@ -27,7 +27,7 @@ StyleResolver& Document::style_resolver()
     return *m_style_resolver;
 }
 
-void Document::normalize()
+void Document::fixup()
 {
     if (is<HTMLHtmlElement>(first_child()))
         return;