Implement Multi-Recipient Payment Orders

[chibie]

User Story

As a sender, I want to create payment orders that can send crypto to multiple recipients so that I can efficiently distribute funds to multiple fiat recipients in a single transaction.

Acceptance Criteria

1. GIVEN a sender creating a payment order,
   WHEN they specify multiple recipients,
   THEN the payment order should be able to handle and process transactions to multiple recipients.

2. GIVEN a sender creating a payment order with multiple recipients,
   WHEN the order is processed,
   THEN the system should correctly distribute the specified amounts to each recipient.

3. GIVEN a sender creating a payment order,
   WHEN they provide an invalid recipient or malformed data,
   THEN the system should validate the input and return appropriate error messages.

Product & Design Links:

Tech Details:

• Update the NewPaymentOrderPayload struct to support an array of recipients.
• Ensure that the system can handle the creation, processing, and validation of payment orders with multiple recipients.
• Update any related database schema to accommodate multiple recipients for a single payment order.
• Ensure proper error handling and validation for the new payload structure.
• Ensure split payment orders are handled efficiently in the indexer service

Open Questions:

• How should the system handle partial failures in a multi-recipient transaction?
• Should there be any limits on the number of recipients per payment order?

Notes/Assumptions:

• It is assumed that the existing system can be extended to support multiple recipients without significant restructuring.
• The system should ensure that each recipient receives the correct amount as specified in the payment order.

[Supa-mega]

Can I tackle this one?