Read real font from AcroForm

[PlPt]

In current implementation the Font on an PdfTextField is "Curier New" hardcoded in PdfTextField class. This causes to crash my automatically filled PDF because in the PDF the Font and Size is Predefined in this fields.

See here: public XFont Font { get; set; } = new XFont("Courier New", 10.0);

[PlPt-ads-tec]

I created an implementation for this, see PullRequest #15