Implement cli wallet command/api endpoint to retrieve voting info

We want to be able to retrieve the list of accounts who voted for certain votable object (committee member, witness, worker, son).

E.g.

get_voters committee_member_id | witness_id | worker_id | son_id | account_id | account_name

The output should be a list of account names that voted for votable object provided. Additional logic should be implemented to identify type of object, especially when account name or id is used, as single account can be owner of committee member, witness, worked or SON.

We also want to be able to retrieve the list of votable objects voted by certain account.

get_votes account_id | account_name

The output should be a list of votable object type and owner accounts names.

For collecting data required, we will use vote_id member of votable object structures. However, index structures are not optimized for fast retrieval of voting info, so retrieval might be slower than what we want.