Resolve "Provide base templates for e-mails generated by apps"

Closes #439 (closed)

aleksis/core/util/email.py

+from typing import Any, Dict, List, Optional
+
+from django.conf import settings
+
+from templated_email import send_templated_mail
+
+from aleksis.core.util.core_helpers import get_site_preferences, process_custom_context_processors
+
+
+def send_email(
+    template_name: str,
+    recipient_list: List[str],
+    context: Dict[str, Any],
+    from_email: Optional[str] = None,
+    **kwargs,
+):
+    processed_context = process_custom_context_processors(settings.PDF_CONTEXT_PROCESSORS)
+    processed_context.update(context)
+    if not from_email:
+        from_address = get_site_preferences()["mail__address"]
+        from_name = get_site_preferences()["general__title"]
+        from_email = f"{from_name} <{from_address}>"
+    return send_templated_mail(
+        template_name=template_name,
+        from_email=from_email,
+        recipient_list=recipient_list,
+        context=processed_context,
+        **kwargs,
+    )