Generate expected schemata for Harbormaster

Summary:
Ref T1191. Nothing too notable here:

• Allow a Lisk object to specify that there's no expectation that a table exists. We have one Harbormaster object and one Token object like this.
• Removed BuildPlanTransactionComment because it's currently unused.

Test Plan:

• Saw ~200 fewer warnings; just ~800 left.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T1191

Differential Revision: https://secure.phabricator.com/D10583