nixie feature

Hack Club gets a lot of returned mail. Some people don't write their own addresses correctly. Sometimes someone at the destination post woke up on the wrong side of the bed (foreign posts write the damnedest things on envelopes they send back sometimes), but regardless of why it's a thing that happens.

We should have Nixie tracking.
This should be spiritually similar to the mark-mailed button (but require HQ login) and accept a reason from a list (IA, NSN, unclaimed, etc)
The flow should be very smooth for whoever is sorting through the piles of mail we get back from the Postal Service.
Like, just scan the QR code and hit the button.
This should notify the recipient and, in an ideal world, prevent them from receiving mail at that address until we can get a corrected address from them.