Bitcoin - Send transactions

[olemis]

Feature description

Create Bitcoin transactions

Is your feature request related to a problem? Please describe.
There is no way to create bitcoin transactions after #208

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

Possible implementation

• List Bitcoin Wallet addresses
• List unspent outputs by address
• Implement Transaction interface for Bitcoin RPC API responses
• Extend Transaction interface to cope with Bitcoin-specific features
• Serialize Bitcoin Transaction
• Implement transaction signing interfaces
• Implement Bitcoin blockchain transaction API for multi-wallet transactions
• Implement P2PKH in Bitcoin blockchain sign service for partial signing with multi-wallet transactions
• Implement P2SH in Bitcoin blockchain sign service for partial signing with multi-wallet transactions
• Implement P2MS signing