feat:etherscan api

[phdargen]

Description

Implements Etherscan API v2 integration:

• get list of Txs for given address including most relevant and nicely formatted metadata (value,fees,from,to,time,function,...)
• also fetches erc20 transfers to better interpret Txs
• get contract info including abi, creator, eth balance, ...
• works for all chains supported by Etherscan (defaults to connected chain)
• requires API key from: https://docs.etherscan.io/etherscan-v2/getting-started/getting-an-api-key

Type of change

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

How Has This Been Tested?

Tested with Claude Desktop, see screenshots

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: