Change 'view all' to 'More' beneath related links lists

The implementation of the 'view all' link beneath groups of related links on production (eg. here — https://www.gov.uk/types-of-school) is based on an outdated design  and should be updated. This branch represents that update. 

The changes here are about to be user tested, but I don't think this should prevent it being merged — it's a small, subtle change.