Revert "Merge pull request #4382 from guardian/revert-pull-request-4381"

This reverts commit d9227ca2dfa630e5cf6fe703c5488809595d2e38, reversing
changes made to 071544d6f5bf607f0195ddf277d726533e6be148.
URLencode SVG
Book feeds can have explicit books shortlisted.

First pass at this feature.
Made param less explicit.

Makes it easier to put in other places.
spacefinder
mobile ad placement
spacefinder tests
renaming splacefinder
removing excess padding for travel component
Merge branch 'master' into commercial-comp-bugs
add survey message on top of any page
- show message only after 3 visits
- don't show message in case it was closed
spacefinder refactor
adding frombottom constraint to spacefinder
assigning a proper ID to the message
fixing layout bug at desktop size
fixing spacefinder rule
fixing layout issue for jobs component
fixing layout of high rel books
adding space above title
spacefinder rule tweaks