Add WooCommerce Composite Products support to tokenized ECE buttons

[frosso]

Description

Now that we rely on the Store API for the ECE integration ( #8525 ), and now that the Composite Products for WooCommerce supports the Store API since v10.3.0, we can improve ApplePay/GooglePay support for product pages of WooCommerce Composite Products.

ApplePay/GooglePay already support all WooCommerce Composite Products on cart & checkout pages.
This ticket is to enhance the WooCommerce Composite Products support on product pages - so that the customer can checkout via GooglePay/ApplePay buttons directly from the "Composite Products" product page.

Acceptance criteria

• GooglePay/ApplePay is displayed on WooCommerce Composite Products product pages
• The customer can checkout with GooglePay/ApplePay with the selections on the product page
• It shouldn't be possible to checkout with the GooglePay/ApplePay button until the Composite Products requirements are satisfied

Designs

N/A

Testing instructions

• Go to the product page for a Composite Products
• Click on the GooglePay/ApplePay button
• You should be able to pay directly from the product page

Dev notes

• Add DOM parsing to a client/tokenized-express-checkout/compatibility/wc-composite-products.js file

Additional context

#8525
#10296