Create module to import DatabaseModel subclasses

Both the initialize_db script and Alembic need to import all
DatabaseModel subclasses so that DatabaseModel.metadata has all the
models attached. Previously this wasn't being done properly, and the
intialize_db script wasn't creating the scraper_result table since it
hadn't been imported.

This commit creates a dedicated module to import all of those classes,
so that both those locations can simply import * from it instead of
needing to import all the models individually. This still isn't great
overall, but it should be less prone to mistakes at least.

tildes/alembic/env.py

@@ -11,22 +11,11 @@ config = context.config
 # This line sets up loggers basically.
 fileConfig(config.config_file_name)
 
-# import all DatabaseModel subclasses here for autogenerate support
-from tildes.models.comment import (
-    Comment,
-    CommentLabel,
-    CommentNotification,
-    CommentVote,
-)
-from tildes.models.group import Group, GroupSubscription
-from tildes.models.log import Log
-from tildes.models.message import MessageConversation, MessageReply
-from tildes.models.scraper import ScraperResult
-from tildes.models.topic import Topic, TopicVisit, TopicVote
-from tildes.models.user import User, UserGroupSettings, UserInviteCode
 
+from tildes.database_models import *
 from tildes.models import DatabaseModel
 
+
 target_metadata = DatabaseModel.metadata
 
 # other values from the config, defined by the needs of env.py,

tildes/scripts/initialize_db.py

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
 """Script for doing the initial setup of database tables."""
-# pylint: disable=wrong-import-order
+# pylint: disable=unused-wildcard-import,wildcard-import,wrong-import-order
 
 import os
 import subprocess
@@ -12,6 +12,7 @@ from alembic import command
 from alembic.config import Config
 from sqlalchemy.engine import Connectable, Engine
 
+from tildes.database_models import *  # noqa
 from tildes.lib.database import get_session_from_config
 from tildes.models import DatabaseModel
 from tildes.models.group import Group

tildes/tildes/database_models.py

@@ -0,0 +1,19 @@
+"""Module that imports all DatabaseModel subclasses.
+
+This module shouldn't really be used for anything directly. It's for convenience so that
+both Alembic and the script for initializing the database can simply import * from here.
+"""
+# pylint: disable=unused-import
+
+from tildes.models.comment import (
+    Comment,
+    CommentLabel,
+    CommentNotification,
+    CommentVote,
+)
+from tildes.models.group import Group, GroupSubscription
+from tildes.models.log import Log
+from tildes.models.message import MessageConversation, MessageReply
+from tildes.models.scraper import ScraperResult
+from tildes.models.topic import Topic, TopicVisit, TopicVote
+from tildes.models.user import User, UserGroupSettings, UserInviteCode