Remove unused EventInfo decorations

The JetSelectorAlg was doing two things:

1. selecting some jets and storing them to storegate
2. adding some kindmatic decoration that describes those jets to EventInfo

I don't think anyone was using the second case. But since people are using our code as a template (see !200 (merged)) we should probably get rid of it if it's not needed.

@frenner this one is mostly your show, did I miss something?