Remove all application callers to "putInSet()"

Summary: Ref T13218. This is the last public-facing API call for loadRelatives/loadOneRelative. This just "primed" objects to make the other calls work and had no direct effects.

Test Plan:

• Ran bin/fact analyze.
• Used bin/storage upgrade -f --apply to apply 20181031.board.01.queryreset.php, which uses LiskMigrationIterator.
• Browsed user list.

Reviewers: amckinley

Reviewed By: amckinley

Subscribers: yelirekim

Maniphest Tasks: T13218

Differential Revision: https://secure.phabricator.com/D19878