list_comments api call improvements

• Improved sql for list_comments
• Removed materialized view from schema: it was not used, it required expensive refreshes
• Some calls are slow comparing to original hived calls
• by_cashout, by_update and by_author_update results are different than expected (waiting for merge from #47 (closed))
• fixed manual tests for list_comments
• Posting a comment will now update active but active is not propagating up at the moment,
• Added post object for database api post
• Added a possibility to convert amount notation to nai notation
• Other minor fixes

hive/db/schema.py

@@ -447,25 +447,6 @@ def setup(db):
           ON CONFLICT DO NOTHING
           ;
           if _parent_author != '' THEN
-            -- update active flag
-            UPDATE
-              hive_posts hpm
-            SET
-              active = _date
-            WHERE
-              hpm.id = (
-                SELECT 
-                  hp.id 
-                FROM 
-                  hive_posts hp
-                INNER JOIN hive_accounts ha ON ha.id = hp.author_id
-                INNER JOIN hive_permlink_data hpd ON hpd.id = hp.permlink_id
-                WHERE
-                  ha.name = _parent_author AND
-                  hpd.permlink = _parent_permlink
-              )
-            ;
-
             RETURN QUERY INSERT INTO hive_posts as hp
             (parent_id, parent_author_id, parent_permlink_id, depth, community_id,
              category_id,