No logical changes here, just moving the code to detect and generate the
message out into a stand alone module (makes it easier to reason about
and possible to unit test).

Co-authored-by: Stefan Penner <stefan.penner@gmail.com>

Co-authored-by: Stefan Penner <stefan.penner@gmail.com>

Fixes a few things:

* Ensures that Embroider has a consistent protocol for ensuring the
  global is bootstrapped
* Allows our override code to be transpiled
* Ensures that any bootstrapping tweaks force us out of "prebuilt" mode
  (allowing that customized bootstrap code to actually run)

Co-authored-by: Stefan Penner <stefan.penner@gmail.com>

Also fixed a few minor errors in the message (wrong version number etc)

Included a list of hardcoded known dormant addons (polyfills mostly) to make
the suggestions more reliable.