title: How to retrieve the column index in ag-grid?
body: <p>In <code>ag-grid</code>, when I want to retrieve the row index I use: </p>
  
  <pre><code>params.node.id
  </code></pre>
  
  <p>However, I couldn't find a way to do the same for columns.
  All that I found is retrieve the <code>columnId</code> which refers to the field variable in the column definition.<br>
  I.e: If this is the column definition:  </p>
  
  <pre><code> {
     headerName: "checkButton 2",
     field: "checkbuttonTwo",
     cellRenderer: "checkButtonComponent",
     width: 150
   }
  </code></pre>
  
  <p>This:   </p>
  
  <pre><code>params.column.getId()  
  </code></pre>
  
  <p>Would return:  </p>
  
  <pre><code> checkbuttonTwo
  </code></pre>
  
  <p>So my question is:<br>
  Is there any way to retrieve the column index? 
  For example: For the second column I would have 2 and so on and so forth.<br>
  Thank you</p>