Parameters:

Example

see fetchRows for custom fetching
 let r = await scrollTable('next', appEnv);
   r=== { data:data, columns: ecolumns}

 if ( r === null) {
    handle when no data was retrieved
 } else {
    handle new data
}

init handler(if specified) will be executed for each row.

Make sure you handle exceptions that are thrown.The library does not handle those and
assumes some higher level code will have a catch

For custom scrolling, pass the scrolling information in the optional third parameter.
The content of the payload depends on whether the source is cas or compute.
For compute see the documentation for rowset in compute service.<https://developer.sas.com/apis/rest/Compute/#get-a-row-set-from-a-data-set>
CAS payload is not as rich the rowset for compute service
At this time the cas is handled thru custom casl code.
Future: use rowset from data management API.
The payload for CAS is as follows
 { qs: {
      start: <number>
      limit: <number>
      format: true|false,
      where: <where string>
};

Please see the restafeditExample in the Tutorial pulldown