Get Project Locked Photographers Endpoint

Locked photographer ids (restriction reason 'photographer', migration 025).

Images shot by these photographers are excluded from share links unless the link opts in — this is what backs permanent licensing restrictions (e.g. agency images that media may use but partners may not).

Single project -> {projectId, lockedPhotographers: [...]}. projectIds[] -> additionally {locksByProject: {"38": [...], ...}} for the All-Projects photographers table, where one photographer can be locked in some of their projects and not others.