Wraps FPDFTextObj_SetTextRenderMode. Allowed values mirror
pdf_text_render_mode()'s names: "fill", "stroke",
"fill_stroke", "invisible", "fill_clip", "stroke_clip",
"fill_stroke_clip", "clip".
Wraps FPDFTextObj_SetTextRenderMode. Allowed values mirror
pdf_text_render_mode()'s names: "fill", "stroke",
"fill_stroke", "invisible", "fill_clip", "stroke_clip",
"fill_stroke_clip", "clip".