Add a factoid command that dumps the lookup down the namespace tree

[simcop2387]

As part of the namespace and factoid update to Postgresql 12, I realized there's a nice command to implement once I finish the other features, use this query

WITH RECURSIVE factoid_lookup_order_inner (depth, namespace, server, alias_namespace, alias_server, parent_namespace, parent_server, recursive, gen_server, gen_namespace) AS (
  SELECT 0 AS depth, namespace, server, alias_namespace, alias_server, parent_namespace, parent_server, recursive, generated_server, generated_namespace
    FROM factoid_config 
    WHERE namespace = ? AND server = ?
  UNION ALL
  SELECT p.depth+1 AS depth, m.namespace, m.server, m.alias_namespace, m.alias_server, m.parent_namespace, m.parent_server, m.recursive, m.generated_server, m.generated_namespace 
    FROM factoid_config m 
    INNER JOIN factoid_lookup_order_inner p 
      ON m.namespace = p.parent_namespace AND m.server = p.parent_server AND p.recursive
),
factoid_lookup_order (depth, namespace, server, alias_namespace, alias_server, parent_namespace, parent_server, recursive, gen_server, gen_namespace) AS (
  SELECT * FROM factoid_lookup_order_inner
  UNION ALL
  SELECT 0, '', '', NULL, NULL, NULL, NULL, false, '', '' WHERE NOT EXISTS (table factoid_lookup_order_inner)
),
get_latest_factoid (depth, factoid_id, subject, copula, predicate, author, modified_time, compose_macro, protected, original_subject, deleted, server, namespace) AS (
      SELECT DISTINCT ON (lo.dept) lo.depth, factoid_id, subject, copula, predicate, author, modified_time, compose_macro, protected, original_subject, f.deleted, f.server, f.namespace
      FROM factoid f
      INNER JOIN factoid_lookup_order lo 
        ON f.generated_server = lo.gen_server
        AND f.generated_namespace = lo.gen_namespace
      WHERE original_subject = ?
      ORDER BY depth ASC, factoid_id DESC
)
SELECT * FROM get_latest_factoid ORDER BY depth ASC, factoid_id DESC;

to implement it, this gives you each lookup that would happen and lets you see each state it'd find at each depth.

[simcop2387]

This has been added. nchain factoid command

17:12:47 < simcop2387> perlbot: nchain
17:12:48 < perlbot> simcop2387: 1. freenode.net:#perlbot -> 2. <*:##NULL>