Stats: add coin holders endpoint

[sl1depengwyn]

Some chains are asking for daily number of native token holders on a network

draft query:

SELECT COUNT(*)
FROM (SELECT address_hash, MAX(day) AS most_recent_day
      FROM address_coin_balances_daily
      WHERE day <= '2024-01-02'
      GROUP BY address_hash) AS sub
         JOIN address_coin_balances_daily AS acbd
              ON sub.address_hash = acbd.address_hash AND sub.most_recent_day = acbd.day
WHERE acbd.value > 0;

[bragov4ik]

@sevenzing should we close it as completed or something remains to be done?