title: Vuetify <v-autocomplete> v-model object instead of array doesn't add correctly
body: <p>I'm doing a hobby project with Vuetify input fields in rows. One of the fields is a v-autocomplete field with 'multiple' prop set. I need to bind this v-autocomplete using v-model to an Object. 
  How do I do this?</p>
  
  <h2>I've tried:</h2>
  
  <ul>
  <li>Overriding the template using v-slot.</li>
  <li>Adding item-value and item-text. This made it display correctly. Nice! Updating doesn't work though. Somehow v-model makes it an array of strings instead of saving as objects. Like so:</li>
  </ul>
  
  <p>Before adding extra items from the list:
  <a href="https://i.imgur.com/UCrxCki.png" rel="nofollow noreferrer">https://i.imgur.com/UCrxCki.png</a> </p>
  
  <p>After adding extra items from the list:
  <a href="https://i.imgur.com/Iwro6DN.png" rel="nofollow noreferrer">https://i.imgur.com/Iwro6DN.png</a> </p>
  
  <p>The v-model list is no longer filled with objects that have their "action" and "amount" props. Instead it makes it a list of Strings</p>
  
  <h2>Code:</h2>
  
  <p>Code in template:</p>
  
  <pre><code>&lt;v-layout wrap v-for="(row, index) in rows" :id="index+1 + 'buildorderRow'" v-bind:key="index"&gt;
     &lt;v-autocomplete
        v-model="row.actions"                                          
        :items="protoss"
        chips                                            
        item-value="action"
        item-text="action"
        multiple
     &gt;
  &lt;/v-layout&gt;
  </code></pre>
  
  <p>Array binded to v-model:</p>
  
  <pre><code>                    actions: [
                          {
                              action: 'Gateway',
                              amount: 5
                          },
                          {
                              action: 'Pylon',
                              amount: 1
                          },
                      ],
  </code></pre>
  
  <h2>Expectation</h2>
  
  <p>I expected it to add any selection to the array while maintaining the model structure. Just like it does for reading the array. For instance if I add an action of "Probe" it should create it like shown below. Amount could also be Null/undefined or even completely left out. The important thing is that it pushes the object with the action prop.     </p>
  
  <p>{ 
  action: 'Probe',
  amount: 1
  }</p>