Show properties of an interface when hovering

[wmertens]

Right now, when you define an interface an you hover over an item with that type, it only shows the name of the interface.

When you control-click, it shows you all the places where this interface is augmented, collapsed, so you need to open each one to see types.
However, when you use control-space to get completion, it shows all properties.

Would it be possible to show the compounded type of an interface on hover?

[mjbvz]

Duplicate of #38040