Add non-fungible EVM transfers (ERC721) support

[tcar121293]

Implement the necessary functions for creating deposit EVM transactions for non-fungible assets (ERC721) following the same structure as the [proposed' v3' SDK restructure] (https://github.com/sygmaprotocol/sygma-sdk/tree/v3).

Implementation details

• Majority of implementation can be already found in v2 version of the SDK

Testing details

• Restructure and update existing unit tests (expand if required)
• Validate manually new example evm-to-evm-erc721-transfer-example is passing on testnet

QA Details

• SDK should support creating a valid non-fungible (ERC721) transfer and estimating fees for it
• SDK should not support any axillary functionalities around ERC721 tokens

Acceptance Criteria

• [ ] Implementing non-fungible (ERC721) EVM transfers following v3 guidlines
• [ ] Restructure and update existing unit tests
• [ ] Add new evm-to-evm-erc721-transfer-example example
• [ ] Validate evm-to-evm-erc721-transfer-example example manually on testnet