Test: Extension details view

[joaomoreno]

• Windows @stevencl
• macOS @waderyan
• Linux @gregvanl

Complexity 2
Tests #10366

When viewing extensions in the Marketplace, you should now be able to see which contributions they bring in.

[stevencl]

I was able to verify that I could see configuration, commands, menus, keybindings, languages, debuggers, grammars, themes, snippets and json validation for a number of extensions from the marketplace.

Couldn't find any bugs though...

[waderyan]

Really like this.

And stoked to find this! Sort Bys are great.