* add evaluateFromMavenPom to piper Utils
* adapt mavenExecute to accept `returnStdout` as parameter. If configured mavenExecute will return the stdout for further processing
* adapt tests of mavenExecute and mavenArtifactVersioning as well as add another exception to CommonStepsTest because mavenExecute will return a String if configured
* Add PiperGoUtils for downloading piper binary
PiperGoUtils provide the link between a Jenkins library step and the library step execution running in a go binary.
It makes sure that an adequate binary is available.
* fix CodeClimate finding
* Remove Delimiter and add download resilience.