Sync with upstream

[agodnic]

Summary

Sync with the latest upstream commit. In particular, add support for the online-only parameter in GET /v2/accounts to search for online accounts.

Note that the parameter is disabled by default.

Performance

The performance of is-online=true lookups can be improved with the following index:

-- create the index
ledgerdb=# CREATE INDEX account_idx_online_only
        ON account ((((account_data ->> 'onl')) = '1'), addr)
        WHERE (NOT deleted) AND ((account_data ->> 'onl') IS NOT NULL) AND ((account_data ->> 'voteLst') IS NOT NULL)
;
CREATE INDEX

-- Verify the index is being used by the query optimizer.
-- This query corresponds to /v2/accounts?limit=10&online-only=true&exclude=all
ledgerdb=# explain (analyze) WITH qaccounts AS (SELECT a.addr, a.microalgos, a.rewards_total, a.created_at, a.closed_at, a.deleted, a.rewardsbase, a.keytype, a.account_data FROM account a WHERE NOT a.deleted AND (a.account_data->>'onl' IS NOT NULL) and (account_data->>'voteLst' IS NOT NULL) and ((a.account_data->>'onl') = '1') ORDER BY a.addr ASC LIMIT 10) SELECT za.addr, za.microalgos, za.rewards_total, za.created_at, za.closed_at, za.deleted, za.rewardsbase, za.keytype, za.account_data FROM qaccounts za ORDER BY za.addr ASC;
                                                                      QUERY PLAN                                                                      
------------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=0.28..37.70 rows=10 width=103) (actual time=0.023..0.038 rows=10 loops=1)
   ->  Index Scan using account_idx_online_only on account a  (cost=0.28..407632.13 rows=108930 width=103) (actual time=0.023..0.036 rows=10 loops=1)
         Index Cond: (((account_data ->> 'onl'::text) = '1'::text) = true)
 Planning Time: 0.268 ms
 Execution Time: 0.049 ms
(5 rows)