Adding support for CBV 2.1 and making changes to pre-hash string accordingly

[Aravinda93]

As per the recommendation from @RalphTro, according to the latest changes to the CBV document (i.e. CBV 2.1) need to adjust the Event Hash Generator pre-hash string as follows:

• sensorElementList should appear before the sensorElement.
• User Extensions that are part of the EPCIS standard fields and should appear directly beneath the respective standard field instead of at the end.
• Adjust the generated Hash-ID to include CBV2.1 instead of CBV 2.0 (?ver=CBV2.1)

@RalphTro Please let us know if something is missing or needs to be corrected.