Draft: refactor follows and update_nofications indexing

Based on !819

hive/db/sql_scripts/postgrest/utilities/get_account_posts.sql

@@ -204,8 +204,8 @@ BEGIN
   IF _post_id <> 0 THEN
     SELECT MIN(hfc.created_at) INTO _min_date
     FROM hivemind_app.hive_feed_cache hfc
-    JOIN hivemind_app.hive_follows hf ON hfc.account_id = hf.following
-    WHERE hf.state = 1 AND hf.follower = _account_id AND hfc.post_id = _post_id;
+    JOIN hivemind_app.follows f ON hfc.account_id = f.following
+    WHERE f.follower = _account_id AND hfc.post_id = _post_id;
   END IF;
 
   _cutoff = hivemind_app.block_before_head( '1 month' );
@@ -227,9 +227,9 @@ BEGIN
             MIN(hfc.created_at) as min_created, 
             array_agg(DISTINCT(ha.name) ORDER BY ha.name) AS reblogged_by
           FROM hivemind_app.hive_feed_cache hfc
-          JOIN hivemind_app.hive_follows hf ON hfc.account_id = hf.following
-          JOIN hivemind_app.hive_accounts ha ON ha.id = hf.following
-          WHERE hfc.block_num > _cutoff AND hf.state = 1 AND hf.follower = _account_id
+          JOIN hivemind_app.follows f ON hfc.account_id = f.following
+          JOIN hivemind_app.hive_accounts ha ON ha.id = f.following
+          WHERE hfc.block_num > _cutoff AND f.follower = _account_id
           AND (_observer_id = 0 OR NOT EXISTS (SELECT 1 FROM hivemind_app.muted_accounts_by_id_view WHERE observer_id = _observer_id AND muted_id = hfc.account_id))
           GROUP BY hfc.post_id
           HAVING (_post_id = 0 OR MIN(hfc.created_at) < _min_date OR ( MIN(hfc.created_at) = _min_date AND hfc.post_id < _post_id ))