Add MC newJO config diff [ATR-28500]

Generates a diff of legacy and newJO trigger configuration for running on MC via runHLT.py/runHLT_standalone.py.

Specifically it:

1. runs with config_only to pickle the config
2. converts the pickle to json (mainly for human readable output)
3. diffs the jsons with confTool, with some suppression of (hopefully) irrelevant outputs
4. runs a script to sanitise some more of the uninteresting content in the output Apart from steps 1-2 this is rather similar to !67000 (merged)

This helps us monitor ATR-28500.