reminder_bot: Add infra for adding reminder bot to every realm.

zerver/lib/onboarding.py

@@ -4,11 +4,24 @@ from django.conf import settings
 from zerver.lib.actions import set_default_streams, bulk_add_subscriptions, \
     internal_prep_stream_message, internal_send_private_message, \
     create_stream_if_needed, create_streams_if_needed, do_send_messages, \
-    do_add_reaction_legacy
+    do_add_reaction_legacy, create_users
 from zerver.models import Realm, UserProfile, Message, Reaction, get_system_bot
 
 from typing import Any, Dict, List, Mapping, Text
 
+def setup_realm_internal_bots(realm: Realm) -> None:
+    internal_bots = [(bot['name'], bot['email_template'] % (settings.INTERNAL_BOT_DOMAIN,))
+                     for bot in settings.REALM_INTERNAL_BOTS]
+    create_users(realm, internal_bots, bot_type=UserProfile.DEFAULT_BOT)
+    bots = UserProfile.objects.filter(
+        realm=realm,
+        email__in=[bot_info[1] for bot_info in internal_bots],
+        bot_owner__isnull=True
+    )
+    for bot in bots:
+        bot.bot_owner = bot
+        bot.save()
+
 def send_initial_pms(user: UserProfile) -> None:
     organization_setup_text = ""
     if user.is_realm_admin: