Fix donor page automation

[CHTJonas]

The donor page automation is currently broken. This needs reimplementing using the PayPal API, probably using webhooks or similar functionality. The data should then be inserted into the appropriate database and table, the pre-existing schema of which is show in a screenshot below:

It would be nice to allow users to configure an alt_name and url if possible e.g. on redirect back to the SRCF.

[alethkit]

Oh dear.
I mean, if we're going to be doing this, I suggest just pulling the plug on PayPal and moving to Stripe.
It has much friendlier developer documentation, and also offers discounted payment processing rates.