Test that exaudfclient doesn't produce debug output in release mode

[tkilias]

Background:

• The udfclient is the program which runs inside the UDF container to communicate with the DB and run the user code
• It is a performance critical part
• Each print to system out and system err take time and should be avoided in a performance critical part

Acceptance Criteria

• Write a test with a UDF that consume a larger input table and use the SCRIPT_OUTPUT_REDIRECT to redirect the output of the udfclient to the test and check if the output is empty (there might be a warning, as the output is small it isn't to much of a problem)
  • you can use the UdfDebugger to redirect the output, as in the following example shown https://github.com/exasol/exasol-python-test-framework/blob/master/tests/udf/udf_debug.py