Add support for album photo type headless evaluation

[phildow]

Headless evaluation is currently limited to performing inference on image files included in a test bundle, the file type. Support for an album-photo type would allow the headless test runner to pull images for local photo albums.

The path value would need to be local id of the PHAsset, which may not be trivial to acquire. We're still assessing if there is enough value here to implement this.