PREF: allow notification ids a larger range

Out of the box we allow 2.2 billion notification, certain exceptionally
bit forums may overflow. This premtively raises the bar to big int.

The trade off is that all forums in the wild store an extra 4 byte in a bunch
of tables.

db/migrate/20230302044150_change_notifications_to_big_int.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+class ChangeNotificationsToBigInt < ActiveRecord::Migration[7.0]
+  disable_ddl_transaction!
+
+  def up
+    change_column :notifications, :id, :bigint
+    change_column :users, :seen_notification_id, :bigint
+    change_column :user_badges, :notification_id, :bigint
+    change_column :shelved_notifications, :notification_id, :bigint
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end

plugins/chat/db/migrate/20230302044151_change_notifications_to_big_int_chat.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class ChangeNotificationsToBigIntChat < ActiveRecord::Migration[7.0]
+  disable_ddl_transaction!
+
+  def up
+    change_column :chat_mentions, :notification_id, :bigint
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end