cli: Add "headers" and "verificationprogress" to -getinfo
cli: Add "headers" and "verificationprogress" to -getinfo

These value are useful to know the current progress of
initial sync, or of catching up.


Former-commit-id: 85eef5bdb39dd5a77096986c9728dc9e6455fe45
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin