fix(woocommerce): image handling in paginated block

[adekbadek]

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Changes proposed in this Pull Request:

Fixes an issue where images in a WooCommerce block with pagination ("Hand-picked Products") had images not loaded when updating the page. This was caused by Perfmatters' optimisation, which was not handled by WC.

How to test the changes in this Pull Request:

1. On trunk, make sure you have Perfmatters and WooCommerce active
2. Add a Campaigns' prompt containing a paginated "Hand-picked Products" block. The pages of the pagination should all include at least two products with images
3. Visit the front-end, observe that on pages other than the one loaded on page load, the images are empty (or only the first one is loaded)
4. Switch to this branch, observe images loading fine when progressing in pagination

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable?
• Have you successfully ran tests with your changes locally?

[miguelpeixe]

I'm unsure if this change is having the intended effect.

In this branch or in trunk with Perfmatters, I can retrieve the thumbnail when changing pages, as long as I don't have a cached version before adding a thumbnail to the product.

If I navigate to a page with a product without a thumbnail, and set a thumbnail, it won't fetch it after navigating to the page again. There's no xhr/fetch request either, so I'm assuming there's some frontend cache at the WC block level.

[adekbadek]

I've re-tested locally and the setup is a bit more complicated. I've edited the testing steps.