R1:7bea116b0045

Change migrations to not rely on "arcanist project" classes

Summary: Ref T7604. Change two migrations to query arcanist project information using `queryfx` directly to avoid the need for the `LiskDAO` fields to exist.

Test Plan:
Ran the following commands to verify that things weren't majorly broken:

- `./bin/storage upgrade --apply phabricator:20150503.repositorysymbols.2.php`
- `./bin/storage upgrade --no-quickstart --namespace test`

Reviewers: #blessed_reviewers, epriestley

Reviewed By…