gdiplus/test: Add GdipReversePath test for Path Pie.
gdiplus: Fix GdipReversePath for mixed Bezier and Line points in subpath. Fixes Reverse_Pie test in Mono: https://github.com/madewokherd/mono/blob/develop/mcs/class/System.Drawing/Test/System.Drawing.Drawing2D/GraphicsPathTest.cs#L3019