Add sorting, enforce foreign keys

ram/portal/migrations/0007_siteconfiguration_items_ordering.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.0.6 on 2022-07-15 12:07
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('portal', '0006_alter_siteconfiguration_site_name'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='siteconfiguration',
+            name='items_ordering',
+            field=models.CharField(choices=[('type', 'By rolling stock type'), ('company', 'By company name'), ('identifier', 'By rolling stock class')], default='type', max_length=10),
+        ),
+    ]