Add fee_payer to ALL operations in get_impacted_account_visitor

[abitmore]

notify_changed_objects() calls get_relevant_accounts() which calls transaction_get_impacted_accounts() or operation_get_impacted_accounts() for some objects:

• proposal_object_type (1.10.x)
• operation_history_object_type (1.11.x)
• impl_transaction_object_type (2.7.x)

Since fee_payer is not added to some operations in get_impacted_account_visitor in db_nofity.cpp, clients won't get notified when changes happened on those objects.

// TODO:  Review all of these, especially no-ops
struct get_impacted_account_visitor
...
   void operator()( const transfer_operation& op )
   {
      _impacted.insert( op.to );
   }

Other related code:

• account_history_plugin.cpp

      operation_get_required_authorities( op.op, impacted, impacted, other ); // fee_payer is added here

      if( op.op.which() == operation::tag< account_create_operation >::value )
         impacted.insert( op.result.get<object_id_type>() );
      else
         graphene::app::operation_get_impacted_accounts( op.op, impacted );

      for( auto& a : other )
         for( auto& item : a.account_auths )
            impacted.insert( item.first );

• operations.cpp

   template<typename T>
   void operator()( const T& v )const 
   { 
      active.insert( v.fee_payer() );

• impacted.cpp

// TODO:  Review all of these, especially no-ops
struct get_impacted_account_visitor
...
   void operator()( const transfer_operation& op )
   {
      _impacted.insert( op.to );
   }

Thanks to @xiangxn for reporting.

[oxarbitrage]

Related code also in elasticsearch plugin that uses the same code as account_history plugin:
https://github.com/bitshares/bitshares-core/blob/master/libraries/plugins/elasticsearch/elasticsearch_plugin.cpp#L122-L131

[abitmore]

Moved this issue to consensus-changing project/milestone to avoid missing changes for new operations.

[abitmore]

Done with #955.