break inherithance SusyNtAna : SusyNtTools

This is a first try at trying to get out of the inheritance
`SusyNtAna : SusyNtTools`.
This pull request is not complete yet, but rather a place where
we can discuss whether this is a sensible approach.

These are the reasons why I think we should go in this direction:
- the inheritance `Susy2LepCutflow : SusyNtAna : SusyNtTools`
hides many of the functions and attributes. For example, we often
access in `Susy2LepCutflow` functions and attributes that are nested
two levels down. I found this hard to follow (often not sure where the
function is being declared)
- we got burnt a couple of times with the attribute `m_anaType`
not being propagated correctly within the constructor
- logically `SusyNtAna` is not a `SusyNtTools`

This change will break many things downstream (see for example
`Susy2LepCutflow`). Comments and suggestions are welcome.