Change some errdetail() to errdetail_internal()

Change some errdetail() to errdetail_internal()

This prevents marking the argument string for translation for gettext,
and it also prevents the given string (which is already translated) from
being translated at runtime.

Also, mark the strings used as arguments to check_rolespec_name for
translation.

Backpatch all the way back as appropriate.  None of this is caught by
any tests (necessarily so), so I verified it manually.