Integration test for business cockpit with c7 adapter

[stefantucek]

Description
As the title suggests, we need to add an end-to-end integration test for the Business Cockpit module of the vanillaBP project, using the C7 adapter. This test should:

1. Spin up a test instance of the Business Cockpit service.
2. Spin up a test instance of a workflow module using C7
3. Execute a typical business workflow (e.g. create/process a business object).
4. Assert that data flows correctly between the cockpit and the C7 adapter.

Acceptance Criteria

• A new test suite under tests/integration/business-cockpit-c7/

• Automated setup/teardown of used services
• At least one successful “happy-path” scenario

• Clear logging
• Green CI run on GitHub Actions upon push