SHA512 code incorrect

### Describe the issue

I am using this secret key: "blxnmpn2m2ebd4glchipydbbsclfvh553vnjqlmuqlzyxlbjsgga"

I tried to use SHA512 and 6-digits and cannot get the authenticator to give me a correct code. This is comparing to the site https://www.authgear.com/tools/totp-authenticator/ where I was able to get a good code.

### Browser

Chrome

### Browser Version

Version 150.0.7871.47 (Official Build) (64-bit)

### Extension Version

8.0.1

Start by reproducing the reported SHA512, six-digit TOTP case in the extension using the supplied secret and compare its code with the Authgear TOTP authenticator. Trace the code path selected for SHA512 and six-digit settings; done means the extension produces the same valid code for this case without breaking other TOTP configurations.

Written by the indexing model from the issue text.