Update Duo Enterprise trial error message

We handled the Duo Pro variation in !189244 (merged) - to use the generic trial failure error. This issue is meant to do the same for the Duo Enterprise variation.

Update the Duo Enterprise trial component so that it uses the generic error - i.e. "We're sorry, your GitLab Duo Enterprise trial could not be created because our system did not respond successfully."

We can likely accomplish this by scrapping the DuoEnterprise specific FormErrorsComponent - example in the attached MR.

• @dstull started a discussion: (+2 comments)

  question:

  Do we still need this component? I think GitlabSubscriptions::Trials::FormErrorsComponent should just work to be called directly?