update AuraScopeClaims to return show IDs instead of slugs

Parent: [STORY] As a programme coordinator/administrato... (aura#102 - closed)

AuraScopeClaims currently exposes the shows "owned" by the user as shows, and the public shows, as a list of the shows' slugs.

This should be a list of the ids.

Additionally, AuraScopeClaims exposes if the user is a supersuer as privileged.

This should be if the user is part of a configurable group of programme managers.