Add 'Name' Property to ObjectInspector

**Describe the solution you'd like**

Some use cases like [Storybook Addon Actions](https://github.com/storybookjs/storybook/blob/master/addons/actions/src/components/ActionLogger/index.tsx#L46) need to have a key for the root node of their object. This is currently done using a `name` prop, which just names the object optionally. It may be useful to have a similar functionality for the ObjectInspector, since there is currently no way to have a top level key.