Add translation service to Brave

Description

We have a translation service that is available in Nightly 1.42.x which can be enabled via brave://flags/#brave-translate-go

Some specific issues have been captured and labeled with brave-translate

This issue is intended to track work required before we can release Brave Translate

Test Plan

https://docs.google.com/document/d/1hADNy20_UIXMe2vXFrTFfpB5NCGK6hBtNVXJBYIJLds/edit

1. No UseBraveTranslateGo feature (Desktop) old bubble to suggest Google extension is used; (Android) no translate UI or attempts to translate pages;

2. (Desktop) UseBraveTranslateGo + enabled Google Translate extension “Google Translate extension” should be used instead of the build-in translation

3. (Desktop) Migration “Offer to translate pages that aren’t in a language you read” preference should be enabled at the first launch with UseBraveTranslateGo feature (if was disabled before) The preference is now unsynced => old version users shouldn’t have the preference changed.

4. (Desktop) Enabled UseBraveTranslateGo feature In general, the behavior should be the same as in Chrome. The difference:

• limited language support;
• no google icon;
• another engine to translate => translated text is expected to be different.

What should be checked:

• foreign language detection (the bubble to translate should be shown when visiting a site in a language that is not listed under settings > languages)
• manual translation from the bubble/context menu.
• “Always Translate" for language (enable “always translate <language>” in bubble and navigate to a site in <language>)
• never translate option for language/site
• UI elements interaction (i.e. change the translate direction/revert/etc)
• Enabling/disabling translate on brave://settings
• Translation from the context menu when page language wasn’t detected

Brave version (brave://version info)

Target release 1.43.x

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? n/a
• Can you reproduce this issue with the nightly channel? n/a

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

Miscellaneous Information:

[8227846265]

Doesn’t seem to work. The prompt for language translation shows to install Google Translate extension

[bsclifton]

@atuchin-m can you please update the docs here too? https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)

Thanks 😄