bug#51733: 27.1; Detect impossible email addresses better

[Eli Zaretskii]

These two tests seem to reveal a bug in the implementation:

  (should (textsec-name-suspicious-p
           "\N{LEFT-TO-RIGHT MARK}\N{LEFT-TO-RIGHT MARK}Lars Ingebrigtsen"))
  (should (textsec-name-suspicious-p
               "\N{LEFT-TO-RIGHT MARK}\N{RIGHT-TO-LEFT MARK}\N{LEFT-TO-RIGHT 
MARK}\N{RIGHT-TO-LEFT MARK}\N{LEFT-TO-RIGHT MARK}Lars Ingebrigtsen")))

LRM and RLM are stateless controls, so they shouldn't be flagged as
suspicious, AFAIU.