First workflow structure to enable HH mgg fits

This is the first step of our current workflow development to enable mgg fits with single-H background.

It includes:

• Align a few naming conventions and sample names with our common parquet files
  • Updating toolsTree2WS, signal and background modeling, and datacard creation steps
• Adding options to support resonant background components. This part will be implemented by Yuxiang
  • modify the resonant fit files
  • package the resonant fit
  • add resonant bkg options for datacard makers
• Setting a pipeline to we get warnings on upstream developments. @jessy is doing this
• Implement systematics to resonant BKGs. @jessy is doing this
• Externalize and unify the cross section and BR numbers that are now hardcoded here -- that reduces places to update numbers (we are sure to use the same as data/MC plots -- And will facilitate if/when we reprocess run2 @jlangfor that would be also useful to SH part no?