Add Synced OwlSliders for Product View Page

This merge adds Synced Sliders to the product view page using OwlSlider2's new functionality:

https://github.com/OwlFonk/OwlCarousel2/issues/580

This is completely unstyled at the moment to provide a basic building block for people who want to style the elements themselves.

Please note this project is still in alpha.