I don't know of any caselaw about this particular new product yet.
I suggest however that if you can buy it in the unlicensed section of a supermarket,
then you can drink it in the street.
Let's be clear about something though.
To those people who ask a question like yours,
but who really mean something like :
"Can I be a smart-mouth with Rangers and Police
who speak to me about having Carlton Zero is No-Alcohol areas?"
My answer would be something like:
"Don't be a smart-mouth, and don't go looking for trouble.
If you get too attitude-y with them, then
you might end up with other infringements,
based on your conduct, rather than about the drink."