feat: adding ens resolution and lookup

[Utkarshbhimte]

Description

This PR integrates ENS name resolution and address lookup functionality to base-mcp. Users can now resolve ENS names to their corresponding Ethereum addresses and perform reverse lookups to find ENS names associated with Ethereum addresses. This enhances user experience by allowing users to interact with human-readable names instead of raw Ethereum addresses.

The implementation adds two new functions:

• resolve_ens_name: Resolves an ENS name (e.g., 'vitalik.eth') to its corresponding Ethereum address
• lookup_ens_address: Performs a reverse lookup to find the ENS name for a given Ethereum address

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Testing was performed using the following methods:

• Manual testing of ENS resolution with known ENS names on Base mainnet
• Manual testing of reverse lookups with known addresses
• Unit tests for both resolution and lookup functions
• Integration tests within the base-mcp environment

Test cases included:

• Resolving ENS names (e.g., vitalik.eth)
• Testing with invalid ENS names
• Reverse lookups for addresses with and without associated ENS names

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Screenshots (if appropriate):