BTHLABS-61: Service layer refactoring

A journey to fix `ValidationError` in Pocket imports turned service
layer refactoring :D

services/backend/testing/hotpocket_backend_testing/fixtures/ui.py

@@ -64,11 +64,25 @@ def pocket_import_banned_netloc_save_spec():
     })
 
 
+@pytest.fixture
+def pocket_import_invalid_url_spec():
+    return PocketImportSaveSpec.model_validate({
+        'title': "This isn't right",
+        'url': 'thisisntright',
+        'time_added': datetime.datetime(
+            2021, 1, 18, 8, 0, 0, 0, tzinfo=datetime.UTC,
+        ),
+        'tags': '',
+        'status': 'unread',
+    })
+
+
 @pytest.fixture
 def pocket_csv_content(pocket_import_created_save_spec,
                        pocket_import_reused_save_spec,
                        pocket_import_other_account_save_spec,
                        pocket_import_banned_netloc_save_spec,
+                       pocket_import_invalid_url_spec,
                        ):
     with io.StringIO() as csv_f:
         field_names = [
@@ -82,6 +96,7 @@ def pocket_csv_content(pocket_import_created_save_spec,
             pocket_import_reused_save_spec.dict(),
             pocket_import_other_account_save_spec.dict(),
             pocket_import_banned_netloc_save_spec.dict(),
+            pocket_import_invalid_url_spec.dict(),
         ])
 
         csv_f.seek(0)