wks: Use templates for the server responses.

* common/helpfile.c (gnupg_get_template): Add arg locale_override and
adjust all callers.
* tools/wks-receive.c (struct receive_ctx_s): Add field ct_language.
(get_language): New.
(new_part): Call it.
(wks_receive): Pass language to the result callback.
* tools/gpg-wks-client.c (short_locale): New.
(main): Get and store the current locale.
(command_create): Fix a glitch for the Posteo hack.  Insert the locale
into the confirmation request.
(send_confirmation_response): Ditto.
* tools/gpg-wks-server.c (struct server_ctx_s): Add field language.
(only_ascii): New.
(struct my_subst_vars_s, my_subst_vars_cb, my_subst_vars): New.
(send_confirmation_request): Use a template.
(send_congratulation_message): Ditto.
(check_and_publish): Pss ctx to send_congratulation_message.
(command_receive_cb): Add arg language.

* doc/wks-utils.txt, doc/wks-utils.de.txt: New.
* doc/Makefile.am (helpfiles): Add them.
--

GnuPG-bug-id: 7381

Note that the subject is not yet translated or templated due to a
missing header encoding function.

doc/wks-utils.de.txt

@@ -0,0 +1,73 @@
+# wks-utils.txt - gpg-wks-server/-client strings (de)  -*- default-generic -*-
+# Written in 2025 by g10 Code GmbH
+#
+# To the extent possible under law, the author(s) have dedicated all
+# copyright and related and neighboring rights to this text to the
+# public domain worldwide.  This text is distributed without any
+# warranty.  You should have received a copy of the CC0 Public Domain
+# Dedication along with this software.  If not, see
+# <https://creativecommons.org/publicdomain/zero/1.0/>.
+# SPDX-License-Identifier: CC0-1.0
+#
+# Note that this template file needs to be UTF-8 encoded.  When looking
+# for a template item, GnuPG scans the help files in the following order
+# (assuming a standard Unix layout):
+#
+#    /etc/gnupg/TEMPLATE.LL_TT.txt
+#    /etc/gnupg/TEMPLATE.LL.txt
+#    /etc/gnupg/TEMPLATE.txt
+#    /usr/share/gnupg/TEMPLATE.LL_TT.txt
+#    /usr/share/gnupg/TEMPLATE.LL.txt
+#    /usr/share/gnupg/TEMPLATE.txt
+#
+# Here TEMPLATE denotes the name of the template (e.g. "mail-tube"),
+# LL_TT denotes the full name of the current locale with the territory
+# (.e.g. "de_DE"), LL denotes just the locale name (e.g. "de").  The
+# first matching item is returned.  To put a dot or a hash mark at the
+# beginning of a text line, it needs to be prefixed with a dot and a
+# space.  A single dot may be used to terminated an entry.  Depending
+# on the template type certain variables (${NAME}) are expanded.
+# Check the man page of the respective tool.
+
+.server.confirm.body
+
+Diese Nachricht wurde auf Ihre Anforderung gesendet, Ihren Schlüssel
+zu veröffentlichen.  Falls Sie solch eine Anforderung nicht gesendet
+haben, so ignorieren Sie bitte diese Nachricht.
+
+[English: This message has been send to confirm your request
+          to publish your key.  If you did not request a key
+          publication, simply ignore this message.]
+
+Viele Mail Software ist in der Lage diese Art von Nachrichten
+automatisch zu verarbeiten.  In diesem Fall sollten Sie diesen Text
+auch nicht sehen.  Falls doch so ist Ihre Mailsoftware veraltet und
+kann mit dieser Nachricht nichts anfangen.  Unter
+
+       https://gnupg.org/faq/wkd.html
+
+finden Sie eine Erklärung, wie Sie solche Nachrichten anderweitig
+verarbeiten können.
+
+
+${sigdelim}
+Weitere Informationen zu GnuPG finden Sie hier: https://gnupg.org
+
+.
+
+.server.publish.congrats
+Hallo!
+
+Der Schlüssel für Ihre Mailadresse '${address}' wurde soeben vom
+Web Key Directory akzeptiert.  Je nach Konfiguration Ihres Providers kann
+es bis zu 15 Minuten dauern, bis er öffentlich sichtbar wird.
+
+Viele Grüße von Ihrem
+
+  Schlüsselveröffentlichungsdienst
+
+
+${sigdelim}
+Weitere Informationen zu GnuPG finden Sie hier: https://gnupg.org
+
+.