Adapted to changes in BaseSink and Entities

Depends on gaudi/Gaudi!1439 (merged)

Goes together with Allen!1324 (merged) Online!823 (merged) Lbcom!682 (merged)

Addresses partially #294

In particular :

• Fixed clashing counter names now that we check them
• Inherit from BaseSink in PhoenixSink and simplify the code
• Rebased FSRSink on BaseSink and simplify it accordingly
• Simplified further FSRSink now that BaseSink has flushing features
• Dropped IncludeJobOptions property from FSRSink
• Better fix for ignoring nlohman unused functions

Note (by @clemenci): I reverted part of the changes in FSRSink as the new version changed too much the behaviour