Steps to reproduce:

When added cmocka tests in DEV-3694 to test refactored item key and SNMP OID substitution, some test cases reported incorrectly, like:

• item[abc],: accepted comma at the end;
• in some echo.sh["{$MACRO}"] cases user macro resolved incorrectly: didn't quote and/or escaped macro.

Task comes from subissue 4 DEV-3694