va: return errors rather than ProblemDetails

[jsha]

In the VA, we'd like to follow the same pattern as the WFE: return a simplified user-friendly error to the user, but also log the full original error.

To do that, we need the top level PerformValidation to have access to the full original error. That means moving the calls to detailedError up the stack, which in turn means making almost every method within the va return error rather than ProblemDetails

[aarongable]

Is this fully closed by https://github.com/letsencrypt/boulder/pull/7313 or do you have a follow-up you want to do?

[jsha]

There's a bit of follow-up I want to do under this issue, which is to actually log the error.