message: Fix - typo in api/ExportXlsxFromDataset name
diff: /// <response code="204">Status204NoContent - User canceled action (e.g. a 'Cancel' button has been pressed on a dialog box)</response>
  /// <response code="401">Status401Unauthorized - Sign-in required</response>
  [HttpPost]
  - [ActionName("ExporXlsxFromDataset")]
  + [ActionName("ExportXlsxFromDataset")]
  [Produces(MediaTypeNames.Application.Json)]
  [ProducesResponseType(StatusCodes.Status200OK, Type = typeof(ExportDataJob))]
  [ProducesResponseType(StatusCodes.Status204NoContent)]
  