1094492: Consumer name length issues in certificate

We were using the type 'directoryName' for SubjectAlternativeName.
It has a size limit that is less than the 255 we use to constrain the
consumer name. Will use type 'uniformResourceIdentifier' instead.
Neither is used as per the type [the starting tag is stripped anyway].
Merge pull request #937 from candlepin/wottop/1094492

1094492: Consumer name length issues in certificate