LibWeb: Implement painting for svg text

The implementation of painting for SVG text follows the same pattern
as the implementation of painting for SVG geometries. However, instead
of reusing the existing PaintableWithLines to draw text, a new class
called SVGTextPaintable is introduced. because everything that is
painted inside an SVG is expected to inherit from SVGGraphicsPaintable.
Therefore reusing the text painting from regular text nodes would
require significant refactoring.

Userland/Libraries/LibWeb/Painting/SVGTextPaintable.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2023, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/Layout/SVGTextBox.h>
+#include <LibWeb/Painting/SVGGraphicsPaintable.h>
+
+namespace Web::Painting {
+
+class SVGTextPaintable final : public SVGGraphicsPaintable {
+    JS_CELL(SVGTextPaintable, SVGGraphicsPaintable);
+
+public:
+    static JS::NonnullGCPtr<SVGTextPaintable> create(Layout::SVGTextBox const&);
+
+    virtual Optional<HitTestResult> hit_test(CSSPixelPoint, HitTestType) const override;
+
+    virtual void paint(PaintContext&, PaintPhase) const override;
+
+    Layout::SVGTextBox const& layout_box() const
+    {
+        return static_cast<Layout::SVGTextBox const&>(layout_node());
+    }
+
+protected:
+    SVGTextPaintable(Layout::SVGTextBox const&);
+};
+
+}