Let's be inspired by esbuild and print out what is actually being packaged.
This should be printed out both on vsce package and vsce publish. We could even have a nice ⚠ on items that are larger than some limit. Only top level files/folders can be printed.

The goal is to make it easier for extensions authors to figure out what is actually being packaged as part of their extension. So they can avoid accidentally packaging something.

fyi @joaomoreno