Pooling not working with unfolding / algorithm-wrapped cuts

As reported on the mailing list pooling of cutflow entries and histograms does not work for unfolding cuts. This is likely due to insufficient initialization calls for algorithms such that the wrapped cuts are not asked to initialize on the SampleFolders levels where they should be pooling.

Marking this as critical as it's also the underlying reason for some merging issues preventing @cbecot from progressing