Add CLI parameters for ePBS builder configuration (#10185)

[0xfornax]

Issue Addressed

Implements #10185.

Proposed Changes

• Adds --builder-urls, --builder-min-bid, and --builder-max-execution-payment for Gloas, and wires the existing --builder-boost-factor into the builder configuration.

• CLI settings will be a fallback for global YAML defaults, preserving Add per-validator builder configuration API #9864 's per-validator precedence and persistence behavior. The order is: per-validator YAML > global YAML > CLI > defaults.

AI assistance

This PR was AI-assisted, but I understand the changes and have tested them thoroughly on a local kurtosis network.

[cla-assistant]

All committers have signed the CLA.

[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[pawanjay176]

Thanks for the PR @0xfornax . The code looks good to me.
My concern is more about policy.

This PR effectively overwrites global builder urls, and other configs with cli params.

This means that you could accidentally delete a config by passing cli params. I think this is okay as long as this is documented. But in terms of actual users, I'm not sure how they would use this.
A potential change in policy is just appending the cli params to the config and throwing an error only if the same builder is present in both lists with different configs.

I would defer to you and @yorickdowne as to which is the better policy based on your experience with users.

[michaelsproul]

For consistency with the rest of Lighthouse, the CLI params should be the default/fallback for the case where no value is specified in the config. I think we should keep that the same here unless there's a very good reason to change it.

[0xfornax]

Thanks for the feedback @michaelsproul and @pawanjay176!

I've adjusted the precedence so it's: Per-validator YAML > global defaults YAML > CLI.

[yorickdowne]

Per-validator yaml likely also covers per-validator keymanager. Just pointing out to please make sure it’s at that level of precedence and doesn’t get overriden by CLI

[michaelsproul]

yeah keymanager writes to the config so it is one and the same