Implement Experimental Mode Rehydrate properly using modules for modern Ember

[mansona]

The way this render mode was implemented before was to inject a vendor file that monkey-patches Ember https://github.com/ember-fastboot/ember-cli-fastboot/blob/v4.1.2/packages/ember-cli-fastboot/vendor/experimental-render-mode-rehydrate.js

This really isn't the right way to do things with modern ember 🙈 we need to make sure that we're importing a module properly and possibly setting module-scope data to tell it to use the new render-mode and not rely on monkey-patching classes 👍

[josemarluedke]

Is rehydration still experimental?

[mansona]

so the fact that it isn't backed into Ember using public APIs means that yes it is. There were a few blockers that held it back when it was being implemented and I think there was supposed to be an RFC that never got submitted.

I think it shouldn't be too hard to get over the line but it should go through the standards process of an RFC 👍