Fix LT-15801 - Stop duplicating headword in referenced entries

* Remove Referenced Sense Headword and Gloss
* Add a wrapper collection so that we can grab the right
  Headword for either LexEntry or LexSense for the Referenced
  Entries
* Implement logic to get the Definition or Gloss from the
* Update default configurations
* Modify the migration code to bring over old checkmarks

Change-Id: Ia5afca80a44de1958a1f808cc8c4caab12eee71b