gpg: Repurpose the ISO defined DO "sex" to "salutation".

* g10/card-util.c (current_card_status): String changes.
(change_sex): Description change.
(cmds): Add "salutation"; keep "sex" as an alias.

Note that we can't change the used values or tags but at least the UI
should show reflect the real purpose of the field.

(cherry picked from commit 166f3f9ec40888e10cb0c51017944bfc57503fc1)

• Signed-off-by: Werner Koch <wk@gnupg.org>