Function legal_action_ids_cached_into 

pub fn legal_action_ids_cached_into(
    state: &GameState,
    decision: &Decision,
    db: &CardDb,
    curriculum: &CurriculumConfig,
    allowed_card_sets: Option<&HashSet<String>>,
    out: &mut LegalActionIds,
)

Compute legal action ids into a reusable output buffer.