Refactor inspect/select logic so that $r contains hooks data

[bvaughn]

Closes #357

This change enables a few things:

• Removes a redundant Bridge message.
• Enables $r to include hooks info for function components.
• Ensures $r is periodically updated if the selected element is re-rendered.

One thing to note is that the hooks value exposed is the internal data structure created by react-debug-hooks so it isn't necessarily as parsable or useful as the props or state objects. Still seems better than nothing though?

[bvaughn]

Eh, I think this is probably a reasonable change. Rolling forward with it.