Use ng-show instead of ng-if for accordions
Use ng-show instead of ng-if for accordions

The Angular directive ng-if will remove elements from the DOM if it
resolves to a 'falsy' value. This commit switches the accordion
elements, to use ng-show, which is similar but does not remove them from
the DOM.

This is more appropriate for our (cosmetic) use case.

Bug: BSM-051

UKHomeOffice/removals_wallboard,UKHomeOffice/removals_wallboard,UKHomeOffice/removals_wallboard