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/GCheckBox.cpp

@@ -1,8 +1,8 @@
 #include <Kernel/KeyCode.h>
 #include <LibGUI/GCheckBox.h>
 #include <LibGUI/GPainter.h>
-#include <SharedGraphics/CharacterBitmap.h>
-#include <SharedGraphics/StylePainter.h>
+#include <LibDraw/CharacterBitmap.h>
+#include <LibDraw/StylePainter.h>
 
 static const char* s_checked_bitmap_data = {
     "         "