title: How do you clear out the sorting icons in ngx-datatable?
body: <p>I'm using ngx-datatable with Angular 5.0 and am implementing sorting with externalSorting set to true as I am doing server side pagination and sorting in the backend. I have a button that on click, resets the data in the table to the data that is displayed on load, so that when a bunch of sorting is done, the user can reset to the original view. It works as intended, however I don't know how to clear out the sorting icons in the column header. Is there a way to do this?</p>