Show fewer items on mobile before hiding
Move show more styles out of container style
Minor refactor: simplify show more JS
Fix test
Use BEM style modifiers for hiding items
Fix silly JS errors
Simplify show more JS
Merge branch 'master' into show-less-on-show-more-on-mobile

Conflicts:
	common/app/views/fragments/containers/slice.scala.html
	common/app/views/fragments/items/facia_cards/standard.scala.html
Fix merge issues
Merge pull request #6064 from guardian/show-less-on-show-more-on-mobile

Show fewer items on mobile before hiding behind "Show More"