refactor(eth): attach ToFilecoinMessage converter to EthCall type

[raulk]

Small refactor to clean things up.

• This converter is better placed as an EthCall method instead of a package-level function.
• The resulting package/module import graph is sane.
• Exporting this as a public method is very helpful for those who use Lotus as a library.

[github-actions]

All checks have passed

[rjan90]

Thanks for the PR! Aarsh will do a pass on it when he is back (he is OOO today).

In the meantime, it looks like you need to run: make gen / make docsgen-cli for the two last checks there to pass.

[Stebalien]

Er, sorry, I didn't see the comment from @rjan90.

[rjan90]

Pushed make gen / make doscgen-cli, to unblock this PR (hope that was okay Raul) so that we can merge it.

[Stebalien]

Test failure looks real.

[raulk]

@rjan90 thanks for running make! ❤️
@Stebalien -- yep, it looks real. I'm investigating.

[rjan90]

Hi @raulk, I'm considering whether it's still worthwhile to finalize this change, or if this PR should get moved back to draft/be closed. I can't recall the specific test that was failing, but it appears to have been resolved, as all checks are currently passing. What do you think?

[rvagg]

👍 this would be a good change; unfortunately things have moved around a bit, the original function being refactored is now in node/impl/eth/utils.go, so this would need a little bit of work.

[rjan90]

I've open a PR with the changes here: #12844. Starting from the master branch seemed to be the simplest approach.