Common Isolation & Selection Frameworks 72X Edition

#4685 + Code review comments and improvement of user interface.
TWiki: https://twiki.cern.ch/twiki/bin/viewauth/CMS/CommonIDAndIsolationFW#Calculating_the_ID_Checksum

Also integrates code into MiniAOD, right now only electron IDs are embedded.

No ID code is run in the standard reconstruction at present.
We will need to talk to Validation/DQM about how to port the IDs that are used there into the framework.

Backports: 71X - #5015, 70X - #5014

@ikrav @Sam-Harper @arizzi
math::deltaR2