Ethereum - Send transactions

[olemis]

Feature description

Create Ethereum transactions

Is your feature request related to a problem? Please describe. There is no way to create Ethereum transactions after #246

Describe the solution you'd like Integrate Ethereum transactions into simple and advanced wallet views

Possible implementation

• [ ] List Ethereum Wallet addresses
• [ ] List unspent outputs by address
• [ ] Implement Transaction interface for Ethereum
• [ ] Extend Transaction interface to cope with Ethereum-specific features
• [ ] Serialize Ethereum Transaction
• [ ] Implement transaction signing interfaces
• [ ] Implement Ethereum blockchain transaction API for multi-wallet transactions
• [ ] Implement P2PKH in Ethereum blockchain sign service for partial signing with multi-wallet transactions
• [ ] Implement Ethereum contract-specific features
• [ ] Implement common ops for ERC20 coins