DRY-up and enforce kwargs for most events

For most events this makes the purpose of each argument clearer at
the point the event is called. It's still worth having a function
for each event type, as this abstracts knowledge of the event label.
Using a schema approach will make adding new events easier.

In the next commit we'll DRY-up the duplication in the tests as well.

app/main/views/find_users.py

@@ -44,7 +44,7 @@ def archive_user(user_id):
                 flash('User can’t be removed from a service - '
                       'check all services have another team member with manage_settings')
                 return redirect(url_for('main.user_information', user_id=user_id))
-        create_archive_user_event(str(user_id), current_user.id)
+        create_archive_user_event(user_id=str(user_id), archived_by_id=current_user.id)
 
         return redirect(url_for('.user_information', user_id=user_id))
     else: