R1:9c5d9e3f4716

Remove "arcanist project" fields

Summary: Ref T7604. Remove these "arcanist project" fields from the `LiskDAO` classes, but leave the data intact (there are no more read/writes to this data).

Test Plan:
- Grepped for calls to these methods.
- Ran `./bin/storage adjust` to check for schema issues.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7604

Differential Revision: https://secure.phabricator.com/D13012