feat: Implement fungible EVM transfers v3

[saadjhk]

Following the proposed v3 SDK restructure, implement/restructure the necessary functions for creating deposit EVM transactions for fungible assets (ERC20).

Implementation details

• Check packages/evm/src/fungible.ts for the interface definitions.
• Make sure to also tackle bug #363 with this refactor

  Testing details

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

QA Details

• New exposed interfaces and functions should allow the same functionalities as the v2 SDK implementation, such as the creation of fungible EVM transfers and the estimation of fees.

Acceptance Criteria

• [x] Implementing fungible EVM transfers following v3 guidlines
• [x] Restructure and update existing unit tests
• [x] Update evm-to-evm-fungible-transfer-example example to use v3 implementation
• [x] Validate evm-to-evm-fungible-transfer-example example manually on testnet

Closes: #371

[wainola]

@saadjhk I think the base of this PR should be v3 branch 🤔

[saadjhk]

@wainola i agree and v3 needs to be first merged with interfaces as well