Adjusted product layout for laptop/md viewports

@texasag @prabinv 
### Adjust Bootstrap's grid for laptop/md viewports
- 3 products per column instead of 4
  - Search page
  - Category page
- This will help prevent product title text overflowing onto the product price inside the md breakpoint as an alternative to lots of media queries with CSS.

TODO: Prevent text overflow in related products row on product page inside md breakpoint