title: How to select a single object by id using @ngrx/entity
body: <p>Using @ngrx/entity I want to select an entity by a single id or an array of entities by an array of ids from an entity map.</p>
  
  <p>I do not want the select subscriptions inside a component to be triggered when the entity collection gets a new element or an entity item changes, which I did not select at all.</p>
  
  <p>This obviously happens to me when I use the selectEntities selector and then pick the IDs from the result.</p>
  
  <p>So how can I select 1 or n items by id from an entity collection?</p>