Sync link_back_to_catalog to bl7 version

[chrisrlc]

WIP:

• Need test for link back from item selected from bento search results
  • Should really think through what controllers needs to share actions from CatalogController, which ones need search history saved and current_search_sessions, Blacklight::SearchContext, Blacklight::SearchState, and etc, esp. related to SearchController vs DatabasesController vs Bookmarks, BookBags, DigitalCollections, etc
• Need test to verify no link back rendered when going from /digitalcollections to /catalog/ID (test exists from /databases --> /catalog/ID)

Follow-up to #2435

• Updates #link_back_to_catalog overridden from a long ago version of blacklight to use updated logic from bl 7
• Allows us to remove overridden #blacklisted_search_session_params that I'd introduced as part of DACCESS-820, 821, 822 - Address bl 8 deprecations #2435
• Explicitly render link back only when current_search_session (matches blacklight) or for bookmarks/book_bags#show, which links back to related controller's index
• Updates analytics tracking label for link from 'back ToSearch' to 'back ToSearch' after verifying with Melissa and Sarah that this is what's actually stored in Matomo