Provide a QR code when signing up a new user with 2FA enabled

[consideRatio]

It becomes quite a bit easier to not need to write in a code for 2FA, but instead scan a QR code. It would be great if we could display such QR code instead of just providing the code in letters and numbers after sign up.

Practically, we should not try to generate images or similar, but instead have some JS to generate what's needed for us based on the letters and numbers in the code we want to represent.

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A quick google provided me with this HTML/CSS/JS with input fields to generate a QR code, what we would need is a function to generate a QR code based on the: domain name, user name, and the 2FA secret generated for the user.