Vault v3 WC Subscriptions integration (2481)

[Dinamiko]

This PR ensures that Vault v3 works correctly with WC Subscriptions.

Acceptance Criteria

• Go to Standard Payments tab and set Subscriptions mode as PayPal Vaulting in Saved payments.

How to enable Vault v3 and Card Fields features:

add_filter('woocommerce.feature-flags.woocommerce_paypal_payments.save_payment_methods_enabled', '__return_true');
add_filter('woocommerce.feature-flags.woocommerce_paypal_payments.card_fields_enabled', '__return_true');

Check if WC Subscriptions works without enabling Vault v3 for both PayPal and ACDC

• As a registered customer purchase a couple of subscriptions (with PayPal and ACDC payments) without enabling Vault v3 and Card Fields features. Ensure you can renewal the subscriptions manually.

Check if existing Vault v2 WC Subscriptions still works when v3 is enabled

• Enable Vault v3 and Card Fields features and renewal the existing subscriptions manually.

Check if new Vault v3 WC Subscriptions works for both PayPal and ACDC

• As a registered customer purchase a couple of subscriptions (with PayPal and ACDC payments) with vault v3 enabled. Ensure you can renewal the subscriptions manually.