Function get_association_state_for_client 

pub async fn get_association_state_for_client(
    context: &impl IdentityContext,
    conn: &impl DbQuery,
    inbox_id: &str,
    to_sequence_id: Option<i64>,
) -> Result<AssociationState, IdentityUpdateError>

get_association_state_with_verifier for a client: a computed state is stored by store_association_state, which emits handle.changed.