Remove RuntimeInfoMiddleware dependency on ILibraryManager by removing the list of packages

[JunTaoLuo]

We need to update the RuntimeInfo middleware in this repo after aspnet/Hosting#514 removed platform services like ILibraryManager.

[davidfowl]

We should just remove the package display.

[JunTaoLuo]

Also clean up UseRuntimeInfoPage to use app.UseMiddleware<RuntimeInfoMiddleware>(options) instead.

[Eilon]

@davidfowl I'm fine with not showing packages, but showing the DLLs is still important. What's the right way to get the list of loaded DLLs?

[davidfowl]

There's no way to do that right now. There's a corefx issue I've been pushing but no progress yet.

[Eilon]

Ok so for this item we'll just remove the package list, and I'll log a new bug to add the loaded DLL list instead.

Do you have a link to the CoreFX bug?

[Eilon]

Here's the bug to list loaded DLLs in the info page: #237