Add the unique ticket code into the downlad CSV file

[Shivangi-ch]

Fixes #9127

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[Shivangi-ch]

@mariobehling after analysing the code I found that, what we see in the order column in csv is the order invoice number['O' + created_at_time + '-' + order.id(primary key)].
Where as in the ticket holder qr code we have [order.identifier + '-' + ticket holder.id(primary key)].
And in the first screenshot order colums it is order.identifier
And for the ticket Id we only have the primary key field 'id'.

I have added order.identifier as the ticket id in the csv now... pls confirm if it is the right value for this!

[Shivangi-ch]

Closing this pull request as the issue has been resolved by another pull request.