Make it possible to set default time zone for EXIF / IPTC data

[thekid]

This pull request adds an optional parameter to exifData() and iptcData() in img.io.ImageMetaData.

Example

use img\io\MetaDataReader;
use io\streams\FileInputStream;
use util\TimeZone;

$reader= new MetaDataReader();
$meta= $reader->read(new FileInputStream($argv[1]));

// Uses the supplied time zone 
$exif= $meta->exifData(new TimeZone('Asia/Muscat'));

// If omitted, uses system's local timezone
$exif= $meta->exifData();

Progress

• Make it possible to optionally pass timezones
• Fix IPTC created date not including time, see https://iptc.org/std/photometadata/specification/IPTC-PhotoMetadata#date-created

[thekid]

Released in https://github.com/xp-framework/imaging/releases/tag/v11.1.0