ENS (pointing to .onion URL) doesn't resolve in Tor private window

[apoorvlathey]

Description

Brave is able to resolve ENS (.eth domains) to their corresponding IPFS webpages in normal mode.
But for the ENS domains that point to .onion URL, the Tor browser tab is not able to resolve it, even after enabling Metamask to work in private window.

Steps to Reproduce

1. Open "Private with Tor" window.
2. Enter duckduckgotor.eth/ in the address bar.

Actual result:

Expected result:

As the Content field of duckduckgotor.eth is onion://3g2upl4pq6kufc4m, so the browser should resolve this ENS into the following onion link: 3g2upl4pq6kufc4m.onion and the corresponding webpage should load:

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave: 1.25.70 Chromium: 91.0.4472.77 (Official Build) (64-bit)
OS: Windows 10 OS Version 2009 (Build 19042.985)

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Yes
• Can you reproduce this issue with the beta channel?
• Yes
• Can you reproduce this issue with the nightly channel?
• Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• No
• Does the issue resolve itself when disabling Brave Rewards?
• No
• Is the issue reproducible on the latest version of Chrome?
• Chrome doesn't support Tor, so it's brave specific.

Miscellaneous Information:

Some other ENS that redirect to Tor for testing:

• Facebook: facebooktor.eth/
• Proton Mail: protonmailtor.eth/
• Tor Project: torprojecttor.eth/
• NYTimes: nytimestor.eth/