Add operators and property owners functionality

- Implemented OperatorListView and OperatorDetailView for managing operators.
- Created corresponding templates for operator listing and detail views.
- Added PropertyOwnerListView and PropertyOwnerDetailView for managing property owners.
- Developed templates for property owner listing and detail views.
- Established relationships between parks and operators, and parks and property owners in the models.
- Created migrations to reflect the new relationships and fields in the database.
- Added admin interfaces for PropertyOwner management.
- Implemented tests for operators and property owners.

property_owners/models.py

@@ -0,0 +1,62 @@
+from django.db import models
+from django.utils.text import slugify
+from django.urls import reverse
+from typing import Tuple, Optional, ClassVar, TYPE_CHECKING
+import pghistory
+from history_tracking.models import TrackedModel, HistoricalSlug
+
+@pghistory.track()
+class PropertyOwner(TrackedModel):
+    """
+    Companies that own park property (new concept, optional relationship)
+    Usually the same as Operator but can be different
+    """
+    name = models.CharField(max_length=255)
+    slug = models.SlugField(max_length=255, unique=True)
+    description = models.TextField(blank=True)
+    website = models.URLField(blank=True)
+
+    objects: ClassVar[models.Manager['PropertyOwner']]
+
+    class Meta:
+        ordering = ['name']
+        verbose_name = 'Property Owner'
+        verbose_name_plural = 'Property Owners'
+
+    def __str__(self) -> str:
+        return self.name
+
+    def save(self, *args, **kwargs) -> None:
+        if not self.slug:
+            self.slug = slugify(self.name)
+        super().save(*args, **kwargs)
+
+    def get_absolute_url(self) -> str:
+        return reverse('property_owners:detail', kwargs={'slug': self.slug})
+
+    @classmethod
+    def get_by_slug(cls, slug: str) -> Tuple['PropertyOwner', bool]:
+        """Get property owner by slug, checking historical slugs if needed"""
+        try:
+            return cls.objects.get(slug=slug), False
+        except cls.DoesNotExist:
+            # Check pghistory first
+            history_model = cls.get_history_model()
+            history_entry = (
+                history_model.objects.filter(slug=slug)
+                .order_by('-pgh_created_at')
+                .first()
+            )
+            
+            if history_entry:
+                return cls.objects.get(id=history_entry.pgh_obj_id), True
+            
+            # Check manual slug history as fallback
+            try:
+                historical = HistoricalSlug.objects.get(
+                    content_type__model='propertyowner',
+                    slug=slug
+                )
+                return cls.objects.get(pk=historical.object_id), True
+            except (HistoricalSlug.DoesNotExist, cls.DoesNotExist):
+                raise cls.DoesNotExist()