Support a brave:// alias to match chrome://

[bbondy]

At the moment the brave:// will just forward to chrome://.
There was a working version of the other way around but it had a lot of patch files and was going to be hard to maintain so we went with this approach instead for now.

Should have similar brave:// links

Examples:

• chrome://welcome/?variant=everywhere
• chrome://downloads/
• chrome://history/
• chrome://bookmarks/
• chrome://extensions/
• chrome://chrome-urls/
• chrome://apps (shortcut on bookmarks toolbar)
• etc...
  

[bbondy]

QA notes: Basically just make sure there are equivalent brave:// pages. I think this broke at some point so if so pls post a new issue and link it here. Don't re-open though as this is estimated work already accounted for and was working at some point.

[btlechowski]

Deleted QA/Needed as the issue regressed #810 and is still not fixed.