Realized unrealized experimentation (#3322)

## Issue Addressed

Add a flag that optionally enables unrealized vote tracking.  Would like to test out on testnets and benchmark differences in methods of vote tracking. This PR includes a DB schema upgrade to enable to new vote tracking style.


Co-authored-by: realbigsean <sean@sigmaprime.io>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
Co-authored-by: sean <seananderson33@gmail.com>
Co-authored-by: Mac L <mjladson@pm.me>

beacon_node/beacon_chain/src/builder.rs

@@ -647,6 +647,7 @@ where
                 store.clone(),
                 Some(current_slot),
                 &self.spec,
+                self.chain_config.count_unrealized.into(),
             )?;
         }