Improve error message when not including name setting up TOTP

[jomaxro (Joshua Rosenfeld)]

The error thrown if a user skips providing a name to the TOTP authenticator isn’t ideal.

[codinghorror (Jeff Atwood)]

Oh that’s not good, we should fix that @eviltrout

[sam (Sam Saffron)]

@martin can take this tomorrow, should only take a few minutes and we can backport to stable with our patch release

[martin (Martin Brennan)]

Fix is building now, will close this off once merged https://github.com/discourse/discourse/pull/9124