Add support for Nimiq Albatross PoS transaction serialization

[sisou]

Description

The transaction format for both signing and sending changed slightly for Nimiq Albatross PoS, to encode optional sender data and support more signature methods (now also supports ECDSA and WebAuthn).

How to test

To test, connect your wallet to a Nimiq PoS testnet node (provided in our joined Telegram channel). To be valid in the testnet, the NETWORK_ID has to be set to 5.

Types of changes

• Breaking change: update transaction serialization for signing and sending

Checklist

• Create pull request as draft initially, unless its complete.
• Add tests to cover changes as needed.
• Update documentation as needed.
• If there is a related Issue, mention it in the description.

If you're adding a new blockchain

• I have read the guidelines for adding a new blockchain.