Update CsvFormatter.php

[zack-carlson]

For Bulk Queries with CSVs that rely on chunking, users may need to return headers with the following values:

'Sforce-Limit-Info' =>
'Sforce-Locator' =>
'Sforce-NumberOfRecords' =>

This proposed change would allow that.

If this would be a breaking change for other instances reading CSV data or too risky, Could there perhaps include a separate formatter for "CSV" such as "csv-headers" or others with "*-headers"?

For example:

$data = Forrest::get(
          "/services/data/v59.0/jobs/query/" . $bulkJob["id"] . "/results?maxRecords=5",
          [],
          [
              "format" => "csv",
              "Accept" => "text/csv"
          ]
      );

Will only return a CSV with 5 rows in the $data attribute. Sending the headers of this request will allow you to loop while "Sforce-Locator" is set to retrieve all rows.