clean up cff/cfi, create sequences, update tests

* Split microAODDefaultOutputCommand/microAODDebugOutputCommand.
* Restore very small flashggPrunedGenParticles but keep the original prunedGenParticles in microAODDebugOutputCommand.
* Move as much as possible into new flashggMicroAODSequence, flashggTagSequence
* Clean up cff/cfi: remove unused duplicate MVA file, rename cfi's and cff's according to conventions given in https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideAboutPythonConfigFile#Including_Standard_Module_defini
* Make simple_*_test.py as minimal as possible using the above changes
in order to make a proper MC-matching, we need to add this.
"keep *_packedGenParticles_*_*",

Probably, we could add a collection of packedGenPhotons to the std event content. Not sure how we could remake the linking to the prunedGenParticles.