Update ETH Gas Tracker extension - API is 404 so directly uses Etherscan API (close issue)

[xmok]

Description

• Extension now uses the Etherscan API
• ❗ API Key is now required (get one for free)

closes #15385. The previous API was a wrapper for Etherscan (reference: https://github.com/0x3studio/0x3studio-api/blob/main/pages/api/gas.ts) so we directly query Etherscan with the drawback it's now BYOK.

Screencast

eth-gas-track.mp4

Checklist

• I read the extension guidelines
• I read the documentation about publishing
• I ran npm run build and tested this distribution build in Raycast
• I checked that files in the assets folder are used by the extension itself
• I checked that assets used by the README are placed outside of the metadata folder

[raycastbot]

Thank you for your contribution! 🎉

🔔 @vinch you might want to have a look.

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