Inspect helpers / resources?

**Is your feature request related to a problem? Please describe.**

I saw that https://github.com/emberjs/ember-inspector/issues/1538 is still open, and inspecting modifiers would be amazingly useful.

Since going full Polaris means that Components are no longer a primitive (but rather a bucket of primitives), it seems like it's important to figure out how to inspect helpers / resources / modifiers / etc (as these can hold lots of state we currently can't inspect with ember-inspector).

**Describe the solution you'd like**

Helpers / Resources / Modifiers visible in the Render Tree
(also the Component Tree renamed to Render Tree or something like that.)

**Describe alternatives you've considered**
I haven't considered anything, because I don't know anything about the debug render tree, but I imagine we need to add hooks into there.

**Additional context**

This will be important for Polaris