title: Angular Material Stepper component prevent going to all the non visited steps
body: <p>I'm using the <a href="https://material.angular.io/components/stepper/overview" rel="noreferrer">Angular Material Stepper</a> component.  </p>
  
  <p>Within my content I have separate buttons that helps the user to move to the next step once the task in the current step is complete.  </p>
  
  <p>I want to prevent the user from visiting the next steps by clicking the step buttons of the stepper component.  </p>
  
  <p>However, I want the user to be able to go back to a previous step via the step buttons of the stepper component.  </p>
  
  <p>I'm not using form inside the stepper. I've seen the Linear property of the component, but it does not suit my requirement.  </p>
  
  <p>In brief, prevent the user from going to the "unvisited" steps by clicking the step buttons of the stepper component. </p>