LibGfx: Move TTF::Rasterizer to its own files

The custom TTF path rasterizer is actually generic enough for it to be
used for other fonts. To make this more clear, it now lives on its own
in the "Font" directory.

Userland/Libraries/LibGfx/Font/PathRasterizer.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2020, Srimanta Barua <srimanta.barua1@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Vector.h>
+#include <LibGfx/Bitmap.h>
+#include <LibGfx/Path.h>
+
+namespace Gfx {
+
+class PathRasterizer {
+public:
+    PathRasterizer(Gfx::IntSize);
+    void draw_path(Gfx::Path&);
+    RefPtr<Gfx::Bitmap> accumulate();
+
+private:
+    void draw_line(Gfx::FloatPoint, Gfx::FloatPoint);
+
+    Gfx::IntSize m_size;
+    Vector<float> m_data;
+};
+
+}