Feature: Show link to invoice on order page

[ndeet]

Useful scenarios are for showing payment receipts on BTCPay end or if the invoice has not expired yet for the customer to return to the invoice page.

See https://chat.btcpayserver.org/btcpayserver/pl/1ywbjj9t1bd4tkn694at7p7kth

[ndeet]

needs more work but the right hook to place it on the order page

function kekeromod_order_details_after_customer_details($order) {
    $url = $order->get_meta('BTCPay_redirect');
    echo "<a href='$url'>$url</a>";
}

add_action('woocommerce_order_details_after_customer_details', 'kekeromod_order_details_after_customer_details', 10, 1);