L2 Subdomain Registering

All Submissions:

[X] Have you followed the guidelines in our Contributing document?
[X] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

All the required contracts from ENS to work were deployed to Arbitrum.

The L1 resolvers use the EIP-5559 to redirect writing calls to the L2 contracts according to the following diagram:

L2 subdomain registering

[X] Have you added an explanation of what your changes do and why you'd like us to include them?
[ ] Have you written new tests for your core changes, as applicable?
[ ] Have you successfully run tests with your changes locally?

The tests will be implemented in a future PR.