modify url to sort works in a collection by title

[snehagunduraoUL]

resolves #642

[rschwab]

I see a couple potential issues with this solution:

1. It will change it for every collection on the A-Z page, I think only Aerials is supposed to be sorted in this way.
2. It will only change it when you visit from the A-Z link, and not if you find it another way for example a LibGuide.

If you use the collection controller before_action you can customize the sort using the blacklight configuration object, and make it only happen on the aerials when there's no query (we want relevance to become the default again after a search is done). See: https://workshop.projectblacklight.org/v7.11.1/sort_fields/ And: https://github.com/UCSCLibrary/ucsc-library-digital-collections/blob/08c55c87d6030f133522224b64ce70f72f0f2935/app/controllers/collections_controller.rb#L13