Add initial l10n support

[TylerLeonhardt]

This leverages the new localization support in our VS Code API and engineering pipelines.

Open questions:

1. I added this in the insiders quality product.json:
   https://github.com/microsoft/vscode-distro/blob/distro/quality/insider/product.json#L1314-L1316
   but maybe I need to add it to all of them and rev the engine to be higher

2. in dd2a688 I tried to localize the parser strings as well... but that failed the tests because the unit tests don't have a vscode implementation. Any idea on how I could mock that?

[jrieken]

I tried to localize the parser strings as well... but that failed the tests because the unit tests don't have a vscode implementation. Any idea on how I could mock that?

I would keep the parser free of vscode-dependencies. It's a bit of duplication but the LanguageValidation-strategy could have a mapping from ValidationError#code to human-readable messages which are then externalized/translated

[TylerLeonhardt]

I leave the parser strings for the next PR then since we can be iterative here.