[enhancement] do .yaml config parsing and puting into channels in groovy instead of python

[mathysgrapotte]

Description of feature

currently .yaml config parsing/splitting into multiple yamls happens in a python process, we would like this to happen in groovy for multiple reasons :

• python programs do not use .yaml files, this is specific to the nextflow pipeline
• would not require stimlus-py container to split .yaml files
• more in line with nf-core/nextflow philosophy