Support translations in vscode web

[jeanp413]

VS Code web now supports localization of the workbench, It's controlled by extensionsGallery.nlsBaseUrl property in product.json pointing to a base url from where to get the localization files. The localzation files are in amd module format (this is different from the localization extension from the marketplace).
We need to investigate how to generate this localization files and from where to served them so they can be consumed by our vscode fork

Link to related analytics from vscode gallery events

vscode-loc repo

Upstream PR

[akosyakov]

As for now it seems very tiny amount of users trying to look up language packs. 1.08% on average in last month.