Cleanup ntuple generation cfis

This removes a lot of code duplication in the NtupleTools/python/*_cfi.py

The desired final states are now passed directly as an argument to make_ntuples_cfg.py

```shell
cmsRun make_ntuples_cfg.py channels="em,mt" [options] inputFiles=file.root
```

See [1] for updated docs.  Any objections  @mverzett / @lgray?

[1] https://github.com/ekfriis/FinalStateAnalysis/blob/master/NtupleTools/test/README.rst