feat: add arb1 support for cowswap

[alfetopito]

Summary

CoW Swap recently launched support for Arbitrum One.

This PR adds support for it on Defillama

Tested locally and it worked fine. Sample order

The addresses used can be checked:

• CoW Protocol's backend endpoint https://api.cow.fi/docs/#/
• Arbitrum One WETH https://arbiscan.io/token/0x82af49447d8a07e3bd95bd0d56f35241523fbab1
• CoW Protocol's EthFlow contract on Arbitrum One https://arbiscan.io/address/0x552fcecc218158fff20e505c8f3ad24f8e1dd33c

[vercel]

@alfetopito is attempting to deploy a commit to the sealed-art Team on Vercel.

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[alfetopito]

Hey there. Reminder to take a look at this. Thanks!

[anxolin]

Hi, is this PR something that could be merged? I guess there's no point on keep it open forever.

I would love to do another PR to add base chain, a new chain supported by CoW Swap, but it would be great to first merge this one, and then I'd gladly create the new PR for base chain