Paramater type inheritence fix

Summary: These parameters wrongly extend List.

Test Plan:
Used createdStart field for a search - didn't get error about "should be a list".
git grep 'extends ConduitListParameterType'.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D15881