Add audit log entries for user roles (#19040)

* Refactor audit log schema

* Add audit log entries for user roles

db/post_migrate/20220824164532_remove_recorded_changes_from_admin_action_logs.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class RemoveRecordedChangesFromAdminActionLogs < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def change
+    safety_assured { remove_column :admin_action_logs, :recorded_changes, :text }
+  end
+end