Reduce mobile ticket scan sensitivity

[atoff]

Mobile ticket scanning via camera is currently very sensitive. We should consider other ways to make this less sensitive and easier to use.

Example Solutions:

• A button for the user to click/hold whilst scanning (like the physical scanner)
• A ticket scanning cooldown (ignore a scanned QR code if it is the same as the previous scanned code scanned within 5 seconds or so)

[atoff]

@streth11 Do you want to have a look at this? Thinking as a minimum could make it skip scanning the previously scanned QR code (i.e. it won't rescan the most recently scanned QR code)

[atoff]

Should be solved by new box office