Update Integration for Merchant and Buyer-Initiated Payment Flags

[jeffpaul]

Square has provided feedback regarding the extension integration and its handling of "merchant initiated" payments. Currently, the integration results in some "card on file" payments being incorrectly flagged as "merchant initiated." This prevents 3D Secure (aka 3DS) from activating on these transactions, exposing merchants to increased chargeback risk.

Problem Summary:

• Some "card on file" payments are incorrectly coded as "merchant initiated."
• This bypasses 3DS, increasing the risk of chargebacks for merchants.

Feedback from Square:

The WooCommerce integration needs to be updated to include the boolean flags for buyer-initiated transactions. These flags are newly exposed in Square’s API and can help distinguish between buyer-initiated and seller-initiated transactions to prevent the above chargeback scenario.

Reference Documentation:

• Square Payments API - Flag Payments

Proposed Solution:

1. Update the extension to support the new boolean flags for buyer-initiated and merchant-initiated transactions as specified in the Square API documentation.
2. Ensure proper handling of "card on file" payments to distinguish between buyer-initiated and merchant-initiated scenarios.
3. Validate that the integration activates 3DS on buyer-initiated payments when required.

Impact:

• Reduces chargeback risk for merchants by ensuring proper 3DS activation.
• Improves compliance with Square’s updated payment processing requirements.

Additional Context:
This update would enhance merchant security and align the extension with the latest Square API capabilities and might be good to bundle with #243.