title: Shopware 6: How to 'tap in' to the update method of an entity?
body: <p>I have tried to find a solution, but maybe I'm searching for the wrong term.</p>
  <p>I want to modify an Entity (a custom one) when the update for the DAL is called. But I cannot seem to find what method to implement in my Entity.
  What I'm looking for is a kind of 'hook'. I thought that maybe I could create a Service and look for a specific event, but there is only events for Products, Categories etc.
  Should I implement an event for my Entity or is there something more general?</p>