Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45273
-- v7: gdiplus: fix shape of CustomLineCap created by GdipCreateAdjustableArrowCap. gdiplus: Add support for widen path with GpCustomLineCap. gdiplus: Move widen_open_figure function to be able to use it from add_anchor function. gdiplus: Add GdipSetCustomLineCapBaseInset implementation. gdiplus: Remove not used LineCustomCap parameter. gdiplus: Add GdipSetCustomLineCapBaseCap implementation.