Draws the glyphs in glyph_item in the specified cairo context,
embedding the text associated with the glyphs in the output if the output format supports it (PDF for example), otherwise it acts similar to [func@show_glyph_string].
The origin of the glyphs (the left edge of the baseline) will be drawn at the current point of the cairo context.
Note that text is the start of the text for layout, which is then indexed by `glyph_item->item->offset`.
| cr |
a Cairo context |
| text |
the UTF-8 text that |
| glyph_item |
a `PangoGlyphItem` |