task: Convert Integration tests

[dgarros]

Component

Python SDK

Task Description

Since the migration to its own repo, the integration have been disabled because they were relying on Infrahub internal code.
Since #183, there is a new way to write integration tests leveraging infrahub-testcontainers

We need to convert or cleanup all tests under tests/integration to work with the new format.

• test_node.py
• test_object_store.py
• test_schema.py
• test_infrahub_client.py
• test_infrahub_client_sync.py
• test_export_import.py

The first couple of tests in test_node.py have been converted already as an example.