docs: rename all mentions of eth2-package and eth-network-package to ethereum-package

[leeederek]

Where did you see the issue in our documentation?

https://docs.kurtosis.com/how-to-local-eth-testnet

Issue description

Rename/update all mentions of eth-network-package and eth2-package to ethereum-package, including links:

• https://docs.kurtosis.com/how-to-local-eth-testnet
• https://docs.kurtosis.com/how-to-compose-your-own-testnet
• https://docs.kurtosis.com/how-to-full-mev-with-eth2-package
• https://docs.kurtosis.com/quickstart
• https://github.com/kurtosis-tech/awesome-kurtosis#kurtosis-web3-starlark-packages

and probably other places

[chunha-park]

#1443 pending review!