LibWeb: Add an SVG::AttributeNames namespace

There are a whole bunch of SVG attributes, and we shouldn't mix them in
with the HTML attributes. This patch adds some of them to the new
namespace, but there are more to be added. :^)

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -221,6 +221,7 @@ set(SOURCES
     Page/Page.cpp
     Painting/BorderPainting.cpp
     Painting/StackingContext.cpp
+    SVG/AttributeNames.cpp
     SVG/SVGElement.cpp
     SVG/SVGGeometryElement.cpp
     SVG/SVGGraphicsElement.cpp