[CSV Exporter] Add Date Format Options with Timezone Handling

[Juiced66]

Description:

Incorporate various date formats (UTC, timestamp, localeString) and timezone handling when exporting data to CSV using native JavaScript and the Intl API.

Tasks:

• Implement formatDate function to handle various date formats and timezones using native JavaScript.
• Update sendExport method to apply date and timezone formatting.
• Allow dateFormat and timezone parameters in exportMeasures.

Example Code:

function formatDate(date: string | number, formatType: string, locale: string): string {
  let dateObj: Date;

  if (typeof date === 'string') {
    dateObj = new Date(date);
  } else {
    dateObj = new Date(date);
  }

  switch (formatType) {
    case 'UTC':
      return dateObj.toISOString();
    case 'timestamp':
      return dateObj.getTime().toString();
    case 'localeString':
      return dateObj.toLocaleString(locale);
    case 'custom':
      return new Intl.DateTimeFormat(locale, {
        year: 'numeric',
        month: '2-digit',
        day: '2-digit',
        hour: '2-digit',
        minute: '2-digit',
        second: '2-digit',
        timeZoneName: 'short'
      }).format(dateObj);
    default:
      throw new Error(`Unsupported date format type: ${formatType}`);
  }
}

// formatter in stream processing 
private async processHits(
  hits: KDocument<MeasureContent>[],
  columns: Column[],
  stream: PassThrough,
  target: "asset" | "device"
) {
  const rows = hits.map(hit =>
    stringify([columns.map(({ header: measureName, isMeasure, path, formatter }) => {
      let value = _.get(hit, path, null);
      if (isMeasure && target === "asset" && hit._source.asset?.measureName !== measureName) {
        return null;
      }
      if (formatter) {
        value = formatter(value);
      }
      return value;
    })])
  );
  stream.write(rows.join(''));
}

Pros:

• Enhances flexibility in date and timezone formatting.
• Provides accurate date representations across different time zones using native JavaScript.
• Opens the road for other formatter to be specified

Cons:

• Increases complexity in date handling logic.
• Requires careful testing for different timezones and formats.