Catalog product price rules should be moved to controller/model

[markshust]

The following template page contains too much code:

https://github.com/magento/magento2/blob/master/app/code/core/Mage/Catalog/view/frontend/product/price.phtml

[magento-team]

Thank you for the suggestion, @markoshust.
We added two stories to our road map:

• Reduced Catalog Component Dependencies
• Simplified Prices Calculation

We're going to make refactoring of this and similar templates, make it simpler and take calculating logic out from the templates in scope of the above stories.