Sets the font and the font size (Tf).
public void SetFont(PdfCanvasFont font, double size)
A font of this document (GetStandard14Font(Standard14Font)).
The font size: the scale from glyph space (thousandths) to text space units.
ISO 32000-2 §9.3.1, Table 103 (Tf and Tfs), and §9.2.2. Allowed outside and inside a text object; part of the
graphics state, so RestoreState() restores the previous font. The font is named in the Font resources.