title: Check if table is filtered
body: <p>is it possible with YADCF to do something like:</p>
  
  <pre><code>yadcf.exGetColumnFilterVal(oTable, 'all')
  </code></pre>
  
  <p>So it returns an array of values of all columns where a filter is applied?</p>
  
  <p>I need to check if there is any filter in any column, also if they are hidden by column visibility. exGetColumnFilterVal is doing the trick, but I would like to avoid something like:</p>
  
  <pre><code>  if (yadcf.exGetColumnFilterVal(oTable, 0) != '') { }
    if (yadcf.exGetColumnFilterVal(oTable, 2) != '') { } 
    if (yadcf.exGetColumnFilterVal(oTable, 3) != '') { } 
    if (yadcf.exGetColumnFilterVal(oTable, 6) != '') { } 
    ...
  </code></pre>
  
  <p>Thank you</p>