Add Drydock logs to the RepositoryOperation UI

Summary:
Depends on D19671. Ref T13197. See PHI873.

Expose logs in the RepositoryOperation UI. Nothing writes the logs yet, so these interfaces are currently always empty.

Test Plan:

Reviewers: amckinley

Reviewed By: amckinley

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T13197

Differential Revision: https://secure.phabricator.com/D19672