title: Vuetify Is there a way to disable/enable a v-text-field append-icon
body: <p>I have a form v-text-field with an append-icon to fire a method when clicked.</p>
  <p>Is there a way to disable/enable conditionally this append-icon ?</p>
  <p>I mean disable not hide.</p>
  <p>(Vuetify version 1.5.24)</p>