All Submissions:

• Have you followed the Optimole Contributing guideline?
• Does your code follow the WordPress' coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

It appears that the $this->settings->use_lazyload() condition is causing the filters to be skipped, and the image_downsize filter is needed to replace the optimized image and fix the issue with WC Cart items.

Closes #753

How to test the changes in this Pull Request:

1. Add a product to the cart.
2. Check if the image is optimized on the same product page when the noticed appears on page that product is added.
3. Go to cart page and check the product images.

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?