feat: add getDnsOffchainData func for gasless dns

[TateB]

changes:

• added getDnsTxtRecords for fetching dns txt records
  • this is under the utils/ namespace because it's more of an internal func
• using getDnsTxtRecords in getDnsOwner
• using strict pattern from resolver methods in getDnsOwner
• added getDnsOffchainData for fetching gasless dns data. it returns resolverAddress/extraData or null.

[sonarcloud[bot]]

Quality Gate failed

Failed conditions

55.1% Duplication on New Code (required ≤ 3%)

See analysis details on SonarCloud