Fix relevance sort (#2773)

- Adds a field to QueryCriteria that determines whether the sort provided is the controller's default sort
- Set this field to true iff sort not in query params. Default it to false
- Override $sort if a new default sort has been set on search state, and the param is true.
- Add tests!

src/Filter/AbstractFilterer.php

@@ -65,7 +65,7 @@ abstract class AbstractFilterer
             }
         }
 
-        $this->applySort($filterState, $criteria->sort);
+        $this->applySort($filterState, $criteria->sort, $criteria->sortIsDefault);
         $this->applyOffset($filterState, $offset);
         $this->applyLimit($filterState, $limit + 1);