Inspect helpers / resources?

[NullVoxPopuli]

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

I saw that #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

[RobbieTheWagner]

With a lot of this, we are at the mercy of what Ember gives us in _captureRenderTree I think. I do not know what all is there or how feasible this is.

[lifeart]

I think we could have it using same approach as described here: #2541 (comment)
(replace ModifierManager to HelperManager)