title: Clearing out selected value for ngx-mat-select-search
body: <p>I am using the <code>"ngx-mat-select-search"</code> npm package for angular and I am looking to provide the users of my application with a default "None" option, or after selecting an item, I would want to give the user the ability to clear out the item and have the dropdown return to its original state with only the placeholder of the input displaying. </p>
  
  <p>As of now, when I select an item from the <code>ngx-mat-select-search</code> I cannot seem to find a way to remove that item and clear out the selection. Is there some way I can do this, maybe I am missing something?  </p>
  
  <p>Here is the link to the documentation/demo of the <code>ngx-mat-select-search</code> - <a href="https://stackblitz.com/github/bithost-gmbh/ngx-mat-select-search-example?file=src%2Fapp%2Fapp.component.html" rel="nofollow noreferrer">click here</a>. As you can see, once an item is selected, there seems to be no way of removing it.</p>
  
  <p>Any help and/or recommendations would be appreciated.</p>
  
  <p>Thank You!</p>