Working branch user/jeffdavis/lp1790231-subject-heading-link-exact-match-search adds "contains=>'exact'" to the query params for subject heading links, forcing an exact-match search when a heading is clicked.
Working branch user/jeffdavis/ lp1790231- subject- heading- link-exact- match-search adds "contains=>'exact'" to the query params for subject heading links, forcing an exact-match search when a heading is clicked.