Fixes empty path issue

[paulushub]

Description

• Fixes issue "Parameter is not valid" exception when document misses width and/or height #1095 (not the original post, but the follow up with tiger.svg file)
• Broken with: Minor optimisations (minor optimisations #1084) commit

The __tiger.svg is marked as passing the tests, but the above commit for 3.4.5 breaks it, by not checking for empty path.
Exception:

Result: TEST FAILED
SVG RENDERING ERROR for __tiger.svg
System.ArgumentException: Parameter is not valid.
   at System.Drawing.Drawing2D.GraphicsPath.get_PathTypes()

Original Code (3.4.4 - https://github.com/svg-net/SVG/blob/v3.4.4/Source/Paths/SvgClosePathSegment.Drawing.cs)

        public override PointF AddToPath(GraphicsPath graphicsPath, PointF start, SvgPathSegmentList parent)
        {
            graphicsPath.CloseFigure();

            var end = start;
            for (var i = graphicsPath.PointCount - 1; i >= 0; --i)
                if ((graphicsPath.PathTypes[i] & 0x7) == 0)
                {
                    end = graphicsPath.PathPoints[i];
                    break;
                }
            return end;
        }

Changed Code (3.4.5 - https://github.com/svg-net/SVG/blob/v3.4.5/Source/Paths/SvgClosePathSegment.Drawing.cs)

        public override PointF AddToPath(GraphicsPath graphicsPath, PointF start, SvgPathSegmentList parent)
        {
            graphicsPath.CloseFigure();

            var end = start;
            var pathTypes = graphicsPath.PathTypes; // ERROR: System.ArgumentException: Parameter is not valid.
            for (var i = graphicsPath.PointCount - 1; i >= 0; --i)
                if ((pathTypes[i] & 0x7) == 0)
                {
                    end = graphicsPath.PathPoints[i];
                    break;
                }
            return end;
        }

Type of change

• Bug fixes (non-breaking change which fixes an issue)
• This change does not require a documentation update
• Resolved review issues (no issue raised).

How Has This Been Tested?

• SvgW3CTestRunner is tested for each supported platform
• Svg.UnitTests tested on command line for each supported platform
• Svg.Benchmarks tested on command line for each supported platform, warnings are as before will be addressed later.