Add a feature that prevents types that inherit from specific types or interfaces from being trimmed

A common pattern in ASP.NET Core is to have well known types or interfaces such as `IComponent`, `Controller` or `Hub`, that a user derives from and the framework reflects over. For e.g.

```C#
void SetProperties(IComponent component, IDictionary values)
{
var properties = component.GetType().GetProperties(...);
SetValues(properties, values);
}

InvokeController(Controller controller, string method)
{
controller.GetMethod(method).Invoke();
}
```

In the component case, having the ability to have type level trimming would help - if the type is referenced, always preserve it's members. In the event of a Controller or a Hub, we want the ability to say always preserve any types that derive from these types since they're primarily discovered and accessed via reflection.