Add comprehensive tests for Parks API and models

- Implemented extensive test cases for the Parks API, covering endpoints for listing, retrieving, creating, updating, and deleting parks.
- Added tests for filtering, searching, and ordering parks in the API.
- Created tests for error handling in the API, including malformed JSON and unsupported methods.
- Developed model tests for Park, ParkArea, Company, and ParkReview models, ensuring validation and constraints are enforced.
- Introduced utility mixins for API and model testing to streamline assertions and enhance test readability.
- Included integration tests to validate complete workflows involving park creation, retrieval, updating, and deletion.

parks/models/companies.py

@@ -1,8 +1,15 @@
 from django.contrib.postgres.fields import ArrayField
 from django.db import models
 from core.models import TrackedModel
+import pghistory
 
+@pghistory.track()
 class Company(TrackedModel):
+    
+    # Import managers
+    from ..managers import CompanyManager
+    
+    objects = CompanyManager()
     class CompanyRole(models.TextChoices):
         OPERATOR = 'OPERATOR', 'Park Operator'
         PROPERTY_OWNER = 'PROPERTY_OWNER', 'Property Owner'