Hygeine: Remove stub/unused links from API

* There are no search links anywhere.
* We don't support pagination within a topic.
* TopicList has pagination has pagination, but the previous field
  was a stub; it is set elsewhere in the class.

Change-Id: I0143455e54e14d2ddebb234c4d2758ee6a2c581d
Merge "Hygeine: Remove stub/unused links from API"