Close #3985: Implement #noqa for i18n

When cross-references in the original paragraph and the translated
paragraph do not match, a warning is emitted.  It is useful, because
it allows to catch mistakes, but it can also be an annoyance since
sometimes it is expected that the cross-references will not match.
For example, a reference that is repeated in the original text may
need to be factored out for good style in the target language.
Another example: if the translator needs to translate a universally
understood term in the source language into a term that not everyone
knows is the translation of this original term, adding a reference to
the glossary can be warranted.  This allows the translated message to
start with '#noqa' in order to disable the warning.

tests/roots/test-intl/literalblock.txt

@@ -49,6 +49,14 @@ code blocks
       literal-block
       in list
 
+.. highlight:: none
+
+::
+
+   test_code_for_noqa()
+   continued()
+
+
 doctest blocks
 ==============
 

tests/roots/test-intl/noqa.txt

@@ -0,0 +1,16 @@
+First section
+=============
+
+Some text with a reference, :ref:`next-section`.
+
+Another reference: :ref:`next-section`.
+
+This should allow to test escaping ``#noqa``.
+
+.. _next-section:
+
+Next section
+============
+
+Some text, again referring to the section: :ref:`next-section`.
+

tests/roots/test-intl/xx/LC_MESSAGES/literalblock.po

@@ -77,6 +77,12 @@ msgid "literal-block\n"
 msgstr "LITERAL-BLOCK\n"
 "IN LIST"
 
+msgid "test_code_for_noqa()\n"
+"continued()"
+msgstr ""
+"# TRAILING noqa SHOULD NOT GET STRIPPED\n"
+"# FROM THIS BLOCK. #noqa"
+
 msgid "doctest blocks"
 msgstr "DOCTEST-BLOCKS"
 

tests/roots/test-intl/xx/LC_MESSAGES/noqa.po

@@ -0,0 +1,46 @@
+# SOME DESCRIPTIVE TITLE.
+# Copyright (C)
+# This file is distributed under the same license as the Sphinx intl <Tests> package.
+# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: \n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2022-01-16 15:23+0100\n"
+"PO-Revision-Date: 2022-01-16 15:23+0100\n"
+"Last-Translator: Jean Abou Samra <jean@abou-samra.fr>\n"
+"Language-Team: \n"
+"Language: xx\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 3.0\n"
+
+#: ../tests/roots/test-intl/noqa.txt:2
+msgid "First section"
+msgstr "FIRST SECTION"
+
+#: ../tests/roots/test-intl/noqa.txt:4
+msgid "Some text with a reference, :ref:`next-section`."
+msgstr "TRANSLATED TEXT WITHOUT REFERENCE. #noqa"
+
+#: ../tests/roots/test-intl/noqa.txt:6
+msgid "Another reference: :ref:`next-section`."
+msgstr ""
+"TEST noqa WHITESPACE INSENSITIVITY.\n"
+"#   \n"
+"   noqa"
+
+#: ../tests/roots/test-intl/noqa.txt:8
+msgid "This should allow to test escaping ``#noqa``."
+msgstr "``#noqa`` IS ESCAPED AT THE END OF THIS STRING. \\#noqa"
+
+#: ../tests/roots/test-intl/noqa.txt:13
+msgid "Next section"
+msgstr "NEXT SECTION WITH PARAGRAPH TO TEST BARE noqa"
+
+# This edge case should not fail.
+#: ../tests/roots/test-intl/noqa.txt:15
+msgid "Some text, again referring to the section: :ref:`next-section`."
+msgstr "#noqa"