Spike: Implementing GrabPay as a new payment method

[FangedParakeet]

Description

We would like to integrate and offer GrabPay as a new payment method supported via Stripe at checkout and in settings. GrabPay is a wallet type payment method available in Singapore and Malaysia.

This issue is just to scope out the implementation, so a satisfactory outcome would be a P2 post describing the capabilities of the payment method and a pathway towards integrating it in WooPayments.

A proof-of-concept is optional, though welcomed, but the actual implementation will likely be scoped out as its own separate project. A rough identification of the necessary tasks to complete this implementation and a loose estimate of the effort required would be admirable, though be aware that we will scope the individual tasks out more thoroughly, once we have identified a feasible and optimal implementation as a result of this spike.

Acceptance criteria

Here is a non-exhaustive list of items worthy of consideration within this spike.

• Settings requirements
• Payment flow
• Feasibility as an individual payment gateway
• Blocks implementation
• Shortcode implementation
• Subscriptions compatibility
• Payment authorisation and order statuses
• Refunds/disputes support
• Comparisons with existing LPMs
• Comparisons with other wallet type payment methods provided by Stripe (e.g. WeChat Pay, Alipay)

Designs

N/A

Testing instructions

N/A

Dev notes

Stripe documentation