LibDraw: Introduce (formerly known as SharedGraphics.)

Instead of LibGUI and WindowServer building their own copies of the drawing
and graphics code, let's it in a separate LibDraw library.

This avoids building the code twice, and will encourage better separation
of concerns. :^)

Libraries/LibGUI/GModel.h

@@ -7,7 +7,7 @@
 #include <AK/RefCounted.h>
 #include <LibGUI/GModelIndex.h>
 #include <LibGUI/GVariant.h>
-#include <SharedGraphics/TextAlignment.h>
+#include <LibDraw/TextAlignment.h>
 
 class Font;
 class GAbstractView;