title: How do you get a list of streams?
body: <p>I need to get a list of all streams (keys) in a database but I can't find a command for it. </p>
  
  <p>I've already tried going over all keys and checking their typebut it is too slow/expensive.</p>
  
  <p>I'd like to do something like <code>XSCAN</code> and get a list of keys like: <code>["stream1", "stream2"]</code></p>