Feature/vote delegate

[DocteurPing]

Summary

I created this PR in order to give the ability to have a delegate address for a masternode. The delegate address will be able to vote for the masternode but won't be able to perform other action on the masternode.

RPCs

• The create and update masternode RPC is now taking a new optional parameter: the delegate address.

Storage

• A new message was created in order to create the new masternode with the delegate address.

Implications

• Storage

  • Database reindex required
  • Database reindex optional
  • Database reindex not required
  • None

• Consensus

  • Network upgrade required
  • Includes backward compatible changes
  • Includes consensus workarounds
  • Includes consensus refactors
  • None

[prasannavl]

Closing as it's no longer relevant.