Modularize Almanac Namespace transactions
Summary: Depends on D19318. Ref T13120. Ref T12414. Move transactions for Almanac Namespaces ("name" is the only meaningful one) to ModularTransactions.
Test Plan:
- Created a new namespace.
- Edited a namespace.
- Tried to choose no name, an invalid name, a duplicate name, and a name in a namespace I can't edit; got appropriate errors.
- Grepped for AlmanacNamespaceTransaction::TYPE_NAME.
Reviewers: amckinley
Reviewed By: amckinley
Maniphest Tasks: T13120, T12414
Differential Revision: https://secure.phabricator.com/D19320