Add integration tests for server-side scripting via gRPC

Summary

Related to caosdb-cpplib#108. The implementation of the rpc call for server-side scripting needs integration tests against an actual running server.

• Test successful SSS
• Test all errors:
  • Timeout
  • Not executable
  • Error during script execution
  • Permission error
  • Script not found
  • Not implemented error for file upload

See also the Python integration tests: https://gitlab.indiscale.com/caosdb/src/caosdb-pyinttest/-/blob/main/tests/test_server_side_scripting.py

Expected Behavior

Actual Behavior

What did the software actually do?

Specifications

• Version: cpplib 0.3
• Platform: any