♻️(backend) change email invitation content

Change the email invitation content. More
document related variables are added.
To benefit of the document inheritance, we moved
the function email_invitation to the document model.

src/backend/core/utils.py

@@ -1,40 +0,0 @@
-"""
-Utilities for the core app.
-"""
-
-import smtplib
-from logging import getLogger
-
-from django.conf import settings
-from django.contrib.sites.models import Site
-from django.core.mail import send_mail
-from django.template.loader import render_to_string
-from django.utils.translation import gettext_lazy as _
-from django.utils.translation import override
-
-logger = getLogger(__name__)
-
-
-def email_invitation(language, email, document_id):
-    """Send email invitation."""
-    try:
-        with override(language):
-            title = _("Invitation to join Docs!")
-            template_vars = {
-                "title": title,
-                "site": Site.objects.get_current(),
-                "document_id": document_id,
-            }
-            msg_html = render_to_string("mail/html/invitation.html", template_vars)
-            msg_plain = render_to_string("mail/text/invitation.txt", template_vars)
-            send_mail(
-                title,
-                msg_plain,
-                settings.EMAIL_FROM,
-                [email],
-                html_message=msg_html,
-                fail_silently=False,
-            )
-
-    except smtplib.SMTPException as exception:
-        logger.error("invitation to %s was not sent: %s", email, exception)