[SON-HIVE Voting] Introduce new vote_id for Hive SONs

The goal is to separate voting for Bitcoin and Hive SONs, so that they can act independently of each others.

Current:

   enum vote_type
   {
      committee,
      witness,
      worker,
      son,
      VOTE_TYPE_COUNT
   };

Wanted:

   enum vote_type
   {
      committee,
      witness,
      worker,
      son_bitcoin,
      son_hive,
      VOTE_TYPE_COUNT
   };

All code affected by this change should be refactored, in a way that enables that Bitcoin SON and Hive SON are considered separate entities.