Localize full plugin data

[msujew]

What it does

Closes #11316

Instead of only localizing the contributes part of plugins (such as menus, commands, etc), we should localize everything, including the name and description property of the plugin.

How to test

1. Assert that the ms-vscode.node-debug2 extension exists as a built-in extension.
2. Open the vsx-registry view and scroll down to the extension. The description should not be %extension.description% but an actual text value.
3. Delete the extension from the plugins directory and restart the server/app.
4. Search for the ms-vscode.node-debug2 extension in the vsx-registry and install it. The description should not change to %extension.description% but continue saying Node.js debugging support.
5. Uninstall the extension again, and change the local to another language. I used zh-cn.
6. Installing the extension again should change the description to a localized value.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[colin-grant-work]

I'm not entirely sure how the data for plugins that have not yet been installed is handled. Searching for node-debug2 while using the application in Chinese, I get this:

And once I install, I get this:

Otherwise, works very well, so if there's no convenient way to fix the content before we download, this is a significant improvement.

[msujew]

@colin-grant-work The open-vsx API does not allow us to set the locale when searching for an extension and only replaces what it can find in the english package.nls.json. We don't have access to the actual localization files while searching for extensions, so that's the best we can do for now.

[colin-grant-work]

This fixes what's in our power to fix, and I see no regressions. 👍