🔧 Cleanup and migrate integration tests and setup

[Nicoretti]

Summary

All important integration tests for the old API should be migrated to the new API and made part of the integration tests suite of the new API.

Tasks

• Use standard test directory layout
• Use Test markers
• Use standard test ci workflows
• Migrate and integrate UDF integration tests
• Add pytest based Integration test settings/configuration
  • Buckets and DB settings used for integration tests
• Add support for a pytest based setup of the integration tests (start db etc.)