Added SS veto IDs

[jkguiang]

Synched against CMS4 SS veto IDs using the same framework as previous synch. In particular, ran lepton IDs on the same set of leptons from each of the same set of 290,100 NanoAOD and CMS4 events.

Muons:

• 105,358 reco muons pass Nano veto ID
• 105,397 reco muons pass CMS4 veto ID = 39 muon difference

Electrons:

• 75,072 reco electrons pass Nano electron veto ID
• 75,124 reco electrons pass CMS4 electron veto ID = 52 electron difference

Also validated that the tight and loose lepton yields match the previously presented synch (cf. these slides).

Also added a few miscellaneous fixes:

• Added some newer JEC info (I forget when we did this and for what, but should be correct)
• Some refactoring of SSSelections.h

[jkguiang]

Note: CI test never ran (waited ~30mins) at least up to the time of writing this comment.