Function execute_admin 

pub fn execute_admin(
    request: &AdminRequest,
    session_ids: &[String],
    session_states: &dyn Fn(&str) -> Option<SessionState>,
    session_threshold: &dyn Fn(&str) -> Option<u32>,
    session_commitments: &dyn Fn(&str) -> Option<usize>,
    session_shares: &dyn Fn(&str) -> Option<usize>,
) -> AdminResponse

Execute an admin request against the coordinator.