Site access updates (#6731)

* Throw error on invalid site access policy

- If ALLOWED_HOSTS is empty, exit
- If CSRF_TRUSTED_ORIGINS is empty, exit
- Closes https://github.com/inventree/InvenTree/issues/6730

* Set parameters for devcontainer

* Update documentation

* Ignore server exit in testing mode

* Add INVENTREE_SITE_URL to CI

* Further CI updates

* Update settings.py

* Unit test updates

* More unit test updates

* Bump API version

* Re-introduce checks in settings.py

- Allow more lenient behaviour in TESTING mode

.github/workflows/qc_checks.yaml

@@ -20,6 +20,7 @@ env:
   INVENTREE_MEDIA_ROOT: ../test_inventree_media
   INVENTREE_STATIC_ROOT: ../test_inventree_static
   INVENTREE_BACKUP_DIR: ../test_inventree_backup
+  INVENTREE_SITE_URL: http://localhost:8000
 
 jobs:
   paths-filter:
@@ -132,6 +133,7 @@ jobs:
       INVENTREE_PYTHON_TEST_SERVER: http://localhost:12345
       INVENTREE_PYTHON_TEST_USERNAME: testuser
       INVENTREE_PYTHON_TEST_PASSWORD: testpassword
+      INVENTREE_SITE_URL: http://localhost:8000
     outputs:
       version: ${{ steps.version.outputs.version }}