p2p: ENS name validation

[avichalp]

Hub needs to normalize ENS names before validating them.

Normalization is the process of canonicalizing a name before running it through the Namehash algorithm. It is important to always normalize all input, because even one little difference (like a capital vs lowercase character) will cause the namehash to be completely different.

For example, NaMe.EtH normalizes to name.eth. This ensures that the correct Registry node is used, no matter how the user types in the name.

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Hubble uses viem's name normalization library for this purpose. There is no equivalent Rust implementation available out of the box. The good news is that the normalization standard is well defined in ENSIP-15. Plus, there are well written implementations to use as a reference:

• python implementation
• js implementation

We need the name normalization for #19. I think, we should implement a module for ENS name normalization within Teleport for now. We could extract it out into its own library once it it is battle tested.