Summary:
The `is_archived` attribute on the `User` model did not explicitly come
back as any particular type. The resulting JSON had the string `"0"` for what's
meant to be a falsey value, but it evaluated to truthy in JS.
`is_archived` now has a getter which explicitly casts it to `boolean` before being
returned anywhere.
Test Plan: Manually tested in dev.
Reviewers: Feld0
Reviewed By: Feld0
Subscribers: #pony.fm
Projects: #pony.fm
Maniphest Tasks: T126
Differential Revision: https://phabricator.poniverse.net/D6
