ENS L2 offchain contenthash resolution

[supermassive]

ENS L2 for wallet address was implemented here https://github.com/brave/brave-browser/issues/22930 In scope of this issues content hash record also should be supported for omnibox scenario.

UI will be covered in separate issue

Also there should be some ui for that per https://github.com/brave/security/issues/966#issuecomment-1225138567 _Make it clear in the UI that an offchain resolution took place ("resolved offchain by XYZ URL") with a place to learn more about what exactly this means._ Maybe like these  

[srirambv]

Verification passed on

Brave	1.45.95 Chromium: 106.0.5249.103 (Official Build) beta (64-bit)
Revision	182570408a1f25ab2731ef5f283b918df9b9f956-refs/branch-heads/5249_91@{#6}
OS	Linux

• Verified steps from brave/brave-core#14945
• Verified offchainexample.eth resolve to ETH address

https://user-images.githubusercontent.com/17010094/195846125-f1a19a33-ebf6-45b1-8d16-abaf523f0e48.mp4

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Verification passed on

Brave	1.45.95 Chromium: 106.0.5249.103 (Official Build) beta (64-bit)
Revision	182570408a1f25ab2731ef5f283b918df9b9f956-refs/branch-heads/5249_91@{#6}
OS	Windows 11 Version 21H2 (Build 22000.978)

• Verified steps from brave/brave-core#14945
• Verified offchainexample.eth resolve to ETH address

https://user-images.githubusercontent.com/17010094/195845465-0ada32f5-d997-458c-bb5b-e6559e8c2cdc.mp4

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Verification passed on

Brave	1.45.95 Chromium: 106.0.5249.103 (Official Build) beta (arm64)
Revision	182570408a1f25ab2731ef5f283b918df9b9f956-refs/branch-heads/5249_91@{#6}
OS	macOS Version 12.6 (Build 21G115)

• Verified steps from brave/brave-core#14945
• Verified offchainexample.eth resolve to ETH address

https://user-images.githubusercontent.com/17010094/195855547-342fdd5d-5713-4e05-95a6-6888685f8716.mov