The empty state now only gets shown when no files exist in the branch.
If the user is reviewing 2 versions with no files, we don't show the state.
Refactors the diff app spec to use Vue test utils.
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/48635
This caused many pain points when working with it.
Part of the data was camel cased the other snake case.
Other parts where snake case & then getting converted in components,
this conversion has the potential for leaking memory.
This changes that & makes it consistent with what it returned from the
API, snake case.