Closes #14438: Database representation of scripts

- Introduces the Script model to represent individual Python classes within a ScriptModule file
- Automatically migrates jobs & event rules

---------

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

netbox/extras/migrations/0110_remove_eventrule_action_parameters.py

@@ -0,0 +1,15 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('extras', '0109_script_model'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='eventrule',
+            name='action_parameters',
+        ),
+    ]