Enable getPreferredSystemLanguages on Linux

[rzhao271]

Ref #169114

This PR passes the locale to Electron on Linux, and then uses the new app.getPreferredSystemLanguages() API to fetch the correct system language to use for the language recommender.

I first tested the API in Electron Fiddle on Ubuntu 22.04, and noticed the API returns values such as en-US or zh-HK. Since the value C is filtered out, it is possible for the returned array to be empty, but there is already a check for that in main.js. A potential issue is that VS Code has language packs for the zh-CN and zh-TW locales specifically, and not for other zh locales. Therefore, more code might be needed to handle other zh locales.

I have tested this change on Ubuntu 22.04 with a custom Insiders and noticed that when the preferred language is Arabic, the window controls are on the left side. However, the window controls are still on the left side even in Stable. I also confirmed the controls are also on the left side for other programs such as Firefox.

I also set the preferred language to French (France) and confirmed that the language recommender works.

[deepak1556]

We don't have WCO on linux, so the behavior should be unaffected by this change.