[site feature] Display extension size

[zardoy]

Hi! I think it would be useful to display install size in WebUI. I always wanted to have something similar to https://packagephobia.com/. I saw thousand of times developers bundling huge .map files or even whole node_modules.

I hope authors in this case will pay more attention to the bundling process. I even saw an extension that had ~110MB .vsix size and more than 200MB on disk. This extension was like installing forever...