feat: vertical project template

Adds the following:

• List template for projects widget
• Adds .eclipsefdn-projects as a new selector for the widget. .featured-projects is kept for backward compatibility.
• Migrates eclipsefdn.projects from JavaScript to TypeScript
• Removes List.js as a dependency and handlebars-jest as dev-dependency
• Implement custom transformer for mustache files to be imported into jest environments. Using a custom transformer allows us to have more control in how these files are transformed - in this case, we can handle partials the same way as we do in webpack.