Adds tenant on power feed (#13300)

* adds tenant on power feed

* cleanup

* adds power feed count on tenant object view

* Misc cleanup; add filterset tests

---------

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

netbox/dcim/migrations/0180_powerfeed_tenant.py

@@ -0,0 +1,20 @@
+# Generated by Django 4.1.8 on 2023-07-29 11:29
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('tenancy', '0010_tenant_relax_uniqueness'),
+        ('dcim', '0179_interfacetemplate_rf_role'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='powerfeed',
+            name='tenant',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.PROTECT, related_name='power_feeds', to='tenancy.tenant'),
+        ),
+    ]