Fix translation of templates with extensions tags (#8)

When trying to translate templates that use tags from extensions different than jinja2.ext.i18n.
At the moment of exporting the literals of those templates the jinja2 engine does not recognize the tags and throws an exception.

This can be reproduced using the "do" statement in a template and trying to define tryton translations.
https://jinja.palletsprojects.com/en/3.1.x/templates/#expression-statement

Co-authored-by: Victor <[email protected]>

report.py

@@ -11,6 +11,18 @@
 from trytond.report.report import TranslateFactory
 
 
+class JinjaExtensionsMixin():
+    JINJA_EXTENSIONS = [
+        'jinja2.ext.i18n',
+        'jinja2.ext.do',
+        'jinja2.ext.loopcontrols',
+    ]
+
+    @classmethod
+    def get_extensions(cls):
+        return cls.JINJA_EXTENSIONS
+
+
 class JinjaTranslator(object):
 
     def __init__(self, method):
@@ -20,13 +32,7 @@ def __init__(self, method):
         self.ungettext = method
 
 
-class Jinja2Report(metaclass=PoolMeta):
-
-    JINJA_EXTENSIONS = [
-        'jinja2.ext.i18n',
-        'jinja2.ext.do',
-        'jinja2.ext.loopcontrols',
-    ]
+class Jinja2Report(JinjaExtensionsMixin, metaclass=PoolMeta):
 
     @classmethod
     def render(cls, action, context):
@@ -36,7 +42,7 @@ def render(cls, action, context):
 
     @classmethod
     def get_environ(cls):
-        env = jinja2.Environment(extensions=cls.JINJA_EXTENSIONS)
+        env = jinja2.Environment(extensions=cls.get_extensions())
         translations = cls.get_translations()
         env.install_gettext_translations(translations)
         env.filters['b64encode'] = b64encode
@@ -72,7 +78,7 @@ def get_attachment(cls, record, name):
             return data
 
 
-class SetTranslationJinja2(metaclass=PoolMeta):
+class SetTranslationJinja2(JinjaExtensionsMixin, metaclass=PoolMeta):
 
     __name__ = 'ir.translation.set'
 
@@ -84,7 +90,7 @@ def extract_report_html(self, content):
             # content with the picky genshi translation extractor,
             # the set-translations process will fail in presence of
             # reports tailored for other template languages like jinja2.
-            env = jinja2.Environment(extensions=['jinja2.ext.i18n'])
+            env = jinja2.Environment(extensions=self.get_extensions())
             for _, _, str_ in env.extract_translations(content.decode()):
                 if str_:
                     yield str_