QR Report and Visitor recognition

Major changes

There are two major changes that were introduced in this version:

1. QR Report
   So this is just a pop up of all the people that are registered with the system WITH their accompanying QR code as noted below:
   
   ^ above is the new "id" icon to represent the qr code report
   
   ^ above is a look at the new QR Code report with all the names next to them
   
   ^ above is an example of the print preview (take note that this is just the print media CSS)

So now it should be fairly obvious what the QR codes are for each person.

2. Visitor recognition
   When adding a person to the system, you now have the option to add them into the system as a visitor:
   
   This actually is stored against a new database column called "is_visitor":
   
   And this actually gets displayed in the account page:
   
   However the new workflow is that if this person is no longer a visitor (that is, they are coming more frequently) then they can be "unticked" from being a visitor and this option actually disappears from the account page.
   

Minor changes

There are a few minor changes that were also introduced (mainly around the UI side of things):

The QR regeneration button is now hidden behind a dropdown AND a confirmation popup.

Checkin-service 0.11.0: https://hub.docker.com/layers/rhinoflower/checkin-service/0.11.0/images/sha256-6cba1c5f0ad04349204853e8a9679ef41fc91a9a52d1256e254ae25b0efb6a04?context=repo

Checkin-UI 0.16.0: https://hub.docker.com/layers/rhinoflower/checkin-ui/0.16.0/images/sha256-3e95bf02f6842e88ac84f764e8913b25ec3cca9b7260ab12110350ca5dc3adc2?context=repo