Split `Offering.payin/outMethod.kind` into specific fields

[jiyoontbd]

Currently, the example for Offering.paymentMethod.kind is something like

Other examples include BANK_SomeBankName or MOMO_MPESA

However, from the perspective of a wallet rendering the kind, we want the ability to break down the type of payment (i.e. bank, momo, etc) from the provider of payment (i.e. Chase, M-Pesa, etc). This is especially useful if a PFI has multiple payment method who has 1 type but many providers of that type, i.e. enabling MOMO via M-PESA or via MTN.

Exact names / how to narrow the definition of kind are to be determined.

[jiyoontbd]

@ethan-tbd would you be able to paste in a screenshot of the page were working on yesterday? 🙏

[ethan-tbd]

For additional context, in order for the Yellow Card PFI to process a SelectedPaymentMethod in the RFQ, the client application is required to specify both a payment type (i.e. bank or mobile money) and the specific provider of that payment type (e.g. United Bank for Africa or M-Pesa). However, since our offering only has a singular kind field to describe the payment method, Yellow Card is using prefixes in their offering PaymentMethod.kind field to denote the payment type and the corresponding suffix to denote the payment provider (e.g. BANK_United Bank for Africa, MOMO_MPESA).

[kirahsapong]

ccing myself to follow along

[mistermoe]

addressed by #261