Move EnPT GUI entry in QGIS to sub-folder

Add these entries:

def group(self):
    return 'Pre-Processing'

def groupId(self):
    return 'PreProcessing'

def name(self):
    return 'EnPTAlgorithm'

def displayName(self):
    return 'EnMAP processing tools algorithm'

It should look like this in QGIS:

image