Initial integration with DFP

Added the basic async calls to DFP to load a commercial component
into the Bottom3 ad slot.
Added the actual DFP file
Now requesting multiple DFP ads using different sizes
Tidying the styling for the paid for content badge
Small tweaks with positioning and sizes to laod
Added a check for the ad test cookie
Abstracted dfp events code to it's own module
Refactored the breakout script
Added dfp-events module
Added adtest cookie to targetting
Switched to loading ads via data attributes. Removed old advertisement feature code
Added a DFP advert switch
Moved the paid for content badge to the correct position
Refactored class name
Fixing merge conflicts
Tidying up
Re-factored the books component to work at the bottom of an article
Loading DFP library by inserting the script to the page
Added a few tests
adding live card ab test