* Register missing C & C inner blocks and update fallback template for older C & C versions
This will fix the issues with missing order summary inner blocks: Coupons (both in C & C blocks) and the Cart header. The issue was happening because, for example, for Cart the coupons were registred on the on frontend, but it just wasn't forced in the attributes. Because it also wasn't added to the PHP fallback layout, the render function didn't include it. For the Checkout block the coupons inner block wasn't registered at all.
* Revert changes to Checkout.php, we don't need to test for inner blocks
* Revert "Revert changes to Checkout.php, we don't need to test for inner blocks"
This reverts commit fc39535f8476d02e35353374d9434a8723458cfa.
* Fix the returned template for older Checkout block iterations
* Fix Cart and Checkout templates to accommodate the Summary order inner blocks
* Hide coupon form div from inner blocks if coubons are not enabled
* Fix checkout coupon tests in checkout
They have been written for logged in user
* Fix Order Summary Heading inner block's default text
* Update comments with better wording
* Revert "Hide coupon form div from inner blocks if coubons are not enabled"
This reverts commit ab09021b923fad4218b3016e47760ad07f6bc960.