openShiftUtils parameters' names are not unified across functions

[lina-is-here]

https://github.com/RedHatInsights/insights-pipeline-lib/blob/master/vars/openShiftUtils.groovy

Examples:

def withNode(Map parameters = [:], Closure body) {
...
def jenkinsSlaveImage = parameters.get('jenkinsSlaveImage', getDefaultSlaveImage(cloud))

def withUINode(Map parameters = [:], Closure body) {
...
def slaveImage = parameters.get('slaveImage', getDefaultSlaveImage(cloud))

def withJnlpNode(Map parameters = [:], Closure body) {
...
def image = parameters.get('image', getDefaultSlaveImage(cloud))

So in 3 functions the same thing is called 3 different names: jenkinsSlaveImage, slaveImage and image.

I think it would be better to unify them to one name.

[bsquizz]

I agree this is confusing... I think we could standardize on 'slaveImage' but I would probably want to leave the old param names in place so we don't break anyone's existing pipelines.