Feat: rework receipt PDF generation so it outputs text and not an image

[bassgeta]

Problem

Our current combo of html2canvas-pro and jsPDF work in the following way

JSX -> Canvas -> PNG -> PDF

which means we can't highlight text in the PDF document since the content is just a PNG image.

Expected behaviour

The PDF should be text and highlightable, so we need to use either just jsPDF with its proprietary syntax or a different library altogether.

[MantisClone]

The PDF Receipt that the Payment Widget offers immediately after a payment will probably not be used. App Builders will probably prefer to generate the PDF Receipts themselves, in a more centralized way, so they can be retrieved at a later time.