Chore: Improve idle memory via more lazy imports (#14599)

* Chore: Import dateparser lazily so processes that never parse dates skip it

* Chore: Import turbohtml lazily in the mail parser

* Chore: Import lxml lazily in the SVG validator

* Chore: Import paperless_ai.indexing lazily in document tasks

* Chore: Import paperless_ai helpers lazily in views

* Chore: Read the OCRmyPDF sRGB profile on first use instead of at import

* Chore: Import pikepdf and img2pdf lazily so startup does not load them

* Chore: Reuse the initialized Django ASGI application for HTTP routing

src/documents/tests/test_api_documents.py

@@ -2686,7 +2686,7 @@ class TestDocumentApi(DirectoriesMixin, ConsumeTaskMixin, APITestCase):
         response = self.client.get("/api/documents/34676/suggestions/")
         self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
 
-    @mock.patch("documents.views.get_ai_document_classification")
+    @mock.patch("paperless_ai.ai_classifier.get_ai_document_classification")
     @override_settings(AI_ENABLED=True)
     def test_suggestions_still_uses_classifier_when_ai_enabled(
         self,