title: SAPUI5 SmartTable dynamically ignore Columns
body: <p>Is there a way to use the <code>ignoredFields</code> property of a sap.ui.comp.smarttable.SmartTable to dynamically ignore columns? The value of <code>ignoredFields</code> should be changed while the app is running. Is the usage of <code>ignoredFields</code> the right way to do this or is there a better way?
  I already tried calling the <code>setIgnoredFields()</code> function of my SmartTable, but it didn't make any effect on my SmartTable, except when I called it in the <code>onInit()</code> function of the respective controller, which of course would defy the dynamic approach i'm looking after.</p>