Pro: Update Payment Intent Description

[garethrees]

A while ago we started updating the Stripe Charge description so that it was easy to identify WhatDoTheyKnow Pro charges in CSV exports for finance reconciliation (#4435). I've verified that this charge update appears to be correctly happening by looking at the event logs for a recent payment.

…scroll down the json panel on the right and see the description value correctly updated…

Currently we do not see this description in the CSV export available to us, but we do for other services. For WhatDoTheyKnow Pro, we just see "Invoice [INVOICE_ID]".

@jaquarone and I think we've narrowed this down to needing to update the payment intent description as well as the charge description.

Here's a TWFY payment intent record – you can see "TheyWorkForYou" in the description in the sidebar.

A WDTK payment intent record is showing the default Invoice ID, which is what we're seeing in the CSV export:

• TWFY updates the payment intent description here: https://github.com/mysociety/theyworkforyou/blob/master/www/docs/api/hook.php#L57-L64
• MapIt updates the payment intent description here: https://github.com/mysociety/mapit.mysociety.org/blob/master/bulk_lookup/views.py#L157
• Alaveteli doesn't update the payment intent description anywhere.