Allow custom Ethereum RPCs for ENS

[ProgrammerWhoPrograms]

Which one does it use currently?

[RangerMauve]

At the moment it's just using whatever is built into Kubo.

https://github.com/AgregoreWeb/agregore-ipfs-daemon/blob/2a0798197769772be810947f2451c10fca03d1ca/go-ipfs/docs/config.md?plain=1#L1772

Exposing this would be a little tricky since we don't have a UI for configuring kubo settings yet.