Dashboard: On "New" simple search widget, populate one column by default

Description

A Search and Sort widget must have at least one column added to it before it can saved. This is checked with validation.

When creating a "New" widget, column validation is being run on selection of the “Widget definition”. Currently no columns are added by default and validation fails at the point at which the definition is selected. This causes an error to be displayed, as shown in the screen shot:

Instead, a column should be displayed by default. The below screenshot shows an example of what will be displayed when the widget definition is first set to "ERM Agreements". This is what is currently displayed when the "Add column" button is selected.

The existing validation is unaffected, this change only affects the default display for the two widget definitions, ERM Licenses and ERM Agreements.