Closes #17653: Add function to trim whitespaces in export templates via jinja environment settings (#19078)

* Create RenderMixin, and unify template_code rendering and exporting

* Join migrations

* Add DEFAULT_MIME_TE constant

* Move RenderMixin to extras.models.mixins, Rename RenderMixin to RenderTemplateMixin

* Add render_jinja2 to __all__

* Rename ConfigTemplateFilterForm rendering FieldSet

* ConfigTemplate lint

* Simplify ExportTemplate get_context

* Fix table order, and add fields for translations

* Update Serializers

* Update forms, tables, graphQL, API

* Add extra tests for ConfigTemplate and ExportTemplate

* Documentation update

* Fix typo

* Misc cleanup

* Clean up template layouts

---------

Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>

netbox/virtualization/views.py

@@ -1,7 +1,6 @@
 from django.contrib import messages
 from django.db import transaction
 from django.db.models import Prefetch, Sum
-from django.http import HttpResponse
 from django.shortcuts import get_object_or_404, redirect, render
 from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
@@ -431,10 +430,7 @@ class VirtualMachineRenderConfigView(generic.ObjectView):
         # If a direct export has been requested, return the rendered template content as a
         # downloadable file.
         if request.GET.get('export'):
-            content = context['rendered_config'] or context['error_message']
-            response = HttpResponse(content, content_type='text')
-            filename = f"{instance.name or 'config'}.txt"
-            response['Content-Disposition'] = f'attachment; filename="{filename}"'
+            response = context['config_template'].render_to_response(context=context['context_data'])
             return response
 
         return render(request, self.get_template_name(), {