Add support to "bundles"

[marcomontalbano]

What I did

I added an attribute kind to the cl-add-to-cart, cl-price, and cl-availability components.

This new attribute indicates whether the code attribute refers to a sku or a bundle (default to sku).

Important

This feature is not fully implement on the cl-availability component. When kind is equal to bundle no information will be displayed and the component will be rendered as an empty box without any size.

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests).
• Make sure to add/update documentation regarding your changes.
• You are NOT deprecating/removing a feature.