Add 'restore-topic' url & various fixes to close/open topic

* Added 'restore-topic' url to the api and topic action menu

* Repurpose urlGenerator.reopen-topic-action

* Tweak close-open-topic output since it needs the topic
  revision as well as the summary revision

Change-Id: I90cf1a677b2e14f7e8836cce335a8f1730370224
Merge "Add 'restore-topic' url & various fixes to close/open topic" into frontend-rewrite