title: Get Tab of TabPanel by id or itemId
body: <p>I have a TabPanel in my View with Tabs. How can I get the instance of a Tab in this Panel and which property should be set id or itemId?</p>
  
  <p>Thanks</p>
  
  <pre><code>openProjectMetaTab: function(project) {
      var tabPanel = this.getTab();
      console.log(tabPanel);
      var mpItemId = 'project-metaTab-' + project.get('id')
      console.log('#'+mpItemId);
      var metaPanel = tabPanel.getComponent(mpItemId);
      console.log(metaPanel);
      if(!metaPanel) {
          tabPanel.add({
              title: project.get('title'),
              closable: true,
              items: [
                  {
                      xtype: 'projectMetaForm',
                      itemId: mpItemId,
                  },
              ],
          }).show();
      }
  }
  </code></pre>