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. :^)

Applications/PaintBrush/PickerTool.cpp

@@ -1,5 +1,5 @@
 #include "PickerTool.h"
-#include <SharedGraphics/GraphicsBitmap.h>
+#include <LibDraw/GraphicsBitmap.h>
 
 PickerTool::PickerTool()
 {