Drop CA8 jets from RECO/AOD, switch to AK8 jets for jet substucture, add softdrop - rebase

Rebase of #6621

This is a long outstanding issue to switch from CA8 to AK8 for jet substructure algorithms.
CA8 jets are obsolete for analyses and in fact one can remove one jet algorithm in RECO by this change.
Also pruning is recommended to be replaced by softdrop for the next Run, therefore add it to RECO.
Here are the changes:

    drop ca8 collection from RECO/AOD, since ak8 jets are recommended instead
    switch from ca8 to ak8 for substructure algorithms in RECO/AOD
    add softdrop to RECO/AOD
    update DQM accordingly
    update default parameters for N-subjettiness and softdrop (these are not run in RECO)
    fix softdrop jet producer