public String getHelperFunction() {
        return helperFunction;
    }
Provides credential from the docker-credential-helper.
Takes inputs @helperFuntion i.e..credential helper name and registry name.
Generates the "docker-credential-helperFuntion get" command 
and gets credentials if exists.
commons/src/main/java/io/hyscale/commons/models/DockerCredHelper.java