[Task] Implement QR code functionality

[JasonBarahan]

Task

Implement the QR code function. As discussed in our prior meeting, we want users to be able to scan a QR code for every event or booth they attend to have it recorded in their stamp book.

Of note is that:

• The QR code should be dynamic. It has a refresh timer (of 10-15 seconds).
• The refresh timer should only be triggered when a user successfully scans the code. This prevents unnecessary overhead (however minimal) and prevents the chances of multiple refresh requests being sent at the same time.
• When a QR code is unable to be generated, the previous QR code should be kept valid until one can be created.
• The previously valid code should not be invalidated immediately after a new one is generated: it should be valid for an additional 0.5-1 second(s) to prevent cases where a QR code becomes invalid as soon as a user scans it.
• A 'club host' panel must be made to allow generation of QR codes.
• While we can store QR codes this is resource-intensive. @bbayazit16 mentioned using HMAC.

Steps

• Implement this feature and request a review
• Pass the review stage