Optimize DX for normalizing an ENS name

[lightwalker-eth]

Above screenshot taken during review of the following PR: namehash/ensawards#60

The issue here is that the normalize we are importing is coming from import { normalize } from "viem/ens";

Therefore we have to explicitly add the "... as NormalizedName" which isn't nice.

Better that we define our own wrapper around normalize in ensnode-sdk that always returns a NormalizedName.

We can also search code across ENSNode to see if there are other opportunities to make use of the new wrapper function.