Add JetFormBuilder (from CrocoBlock) extension support

[rvdsteege]

From customer:

Ik vroeg mij af of Pronamic inmiddels ook ondersteunt wordt voor de JetFormBuilder van CrocoBlock. CrocoBlock is momenteel onwijs populair vanwege de ongekende mogelijkheden.

The free plugin includes support for PayPal and the jet-form-builder/gateways/register action allows other gateways to integrate.

• https://crocoblock.com/plugins/jetformbuilder/

Internal Help Scout ticket: https://secure.helpscout.net/conversation/1568823841/22377

[patrickadam]

Yes. We use it regularly with GF, but would also like to use it with JetFormBuilder.

I had not seen this topic, so I sent Pronamic a message. I got this response: A few years ago we received the same question from you about JetFormBuilder support. Since then we (reference to this topic) have also started tracking requests for this from other users, but there have been none in the past 3 years.