The SVGContext is a leftover from when SVG properties were more ad-hoc.
All properties are now (for better or worse) treated as CSS properties
(or handled elsewhere). This makes the SVGContext's fill/stroke
inheritance handling unnecessary.
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.
