Milestone-1 (proposed)

Milestone-1 - Basic auction

See the delivery PR.

Features:

1. Start & close period
2. Set auction subject:

• NFTs (ERC721), or
• Domain name (DNS)

3. Accept bids
4. Find winner (Basic auction)
5. Pluggable reward logic payout to winner
   in accordance to subject: a NTF collection or Domain name
6. Payout to auction owner and other bidders