Transform from Accord Project templates to pdf forms

[jeromesimeon]

Currently we can generate pdf from Accord Project contracts. It would be nice if we could generate a pdf form from a template.

The idea would be to generate form field for Accord Project template variables. A user could then fill in the content of the form directly within pdf.

This could work well along with the ability to maintain Accord Project metadata within the form, maybe along the lines of #351

Notes:

• There isn't yet support for pdf forms in pdfmake but there is support for it in the underlying library. See issue here: Allow PDF to create PDF forms bpampuch/pdfmake#269