Provide "almanac.binding.search" and "almanac.binding.edit"

Summary:
Depends on D19338. Ref T13120. Ref T12414. These are the last of the new API methods.

This stuff still doesn't work:

• You can't actually enable/disable bindings yet. I want to take a look at the use cases and consider changing "disabled" to "status", or providing a different way to solve the problem.
• You can't edit properties via the API. I expect to enable this for all AlmanacPropertyInterface objects with an extension in a future change.

Test Plan:

• Searched for bindings via API.
• Viewed binding web UI for API methods.
• Created bindings via API.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13120, T12414

Differential Revision: https://secure.phabricator.com/D19340