BLIK: Determine WC Subscription support

[cesarcosta99]

Ensure that the BLIK is compatible with WooCommerce Subscriptions. This includes handling initial payments, renewals, and special cases such as free trials and zero-value payments.

pcrvl0-1E6-p2 determined BLIK doesn't support WooCommerce Subscriptions given how the payment flow works. But we'll be looking in more detail during implementation to confirm.

• Determine if WooCommerce Subscriptions is supported for BLIK.

If supported:

• Ensure support for different subscription types:
  • Simple subscription.
  • Variable subscription.
  • Free trial subscription.
  • Zero-value payments.
• Ensure the subscription pay for order flow works correctly.
• Verify that automatic renewals process successfully.
• Ensure failed payment retries and subscription status updates are handled successfully.
• Add unit tests to cover subscription-related payment flows.

[cesarcosta99]

As flagged in #3955, BLIK doesn't support tokenization, which by extension, makes it incompatible with WooCommerce Subscriptions.