Function apply_power_levels_pdu 

async fn apply_power_levels_pdu(
    services: &Services,
    body: &Args<Request>,
    preset: &RoomPreset,
    version_rules: &RoomVersionRules,
    sender_user: &UserId,
    room_id: &RoomId,
    state_lock: &RoomMutexGuard,
) -> Result