feat: Standardize subdomain `register` call

[pikonha]

Feature Request

Describe the Feature Request

The OffchainResolver interface establishes a single register function for both DB and L2 domains.

Describe Preferred Solution

Use the same register function for registering subdomains:

function register(
    bytes32 parentNode,
    string calldata label,
    address owner,
    uint256 duration,
    bytes32 secret,
    address resolver,
    bytes[] calldata data,
    bool reverseRecord,
    uint16 fuses,
    bytes memory extraData
)
    external
    payable;

Describe Alternatives

Related Code

Additional Context

[pikonha]

done by #220