dynamically generated notifs

Some of the notifications can be extracted from DB tables with SQL query. This allows us to avoid redundancy and save db space.

hive/db/db_state.py

@@ -110,6 +110,9 @@ class DbState:
             'hive_votes_voter_id_idx',
             'hive_votes_block_num_idx',
 
+            'hive_subscriptions_block_num_idx',
+            'hive_communities_block_num_idx',
+
             'hive_accounts_ix5', # (cached_at, name)
 
             'hive_post_tags_tag_id_idx'
@@ -322,7 +325,7 @@ class DbState:
             from hive.indexer.accounts import Accounts
             names = SteemClient().get_all_account_names()
             Accounts.load_ids()
-            Accounts.register(names, '1970-01-01T00:00:00')
+            Accounts.register(names, '1970-01-01T00:00:00', 0)
             Accounts.clear_ids()
             cls._set_ver(6)