vscode-extension-vscode is deprecated

[coliff]

This extension currently uses 'vscode' dependency (https://github.com/Microsoft/vscode-extension-vscode#readme) which is deprecated.

They suggest to use @types/vscode and vscode-test instead.

We should look to migrate to those as they have fewer dependencies, allow greater flexibility in writing tests and will continue to receive updates.

Migration guide: https://code.visualstudio.com/api/working-with-extensions/testing-extension#migrating-from-vscode