Schema version 6: lookup fastboot info

[xg-wang]

Implicit injection is deprecated https://deprecations.emberjs.com/v3.x#toc_implicit-injections

Fixes #819
Depends on #822

This is breaking change because user needs to upgrade to compatible fastboot

[rwjblue]

I think we can do this without a breaking change. The deprecation does nto fire when you call instance.inject it gets called when you the FastBoot service is created. So we can always call instance.inject then we can update fastboot service to use a caching getter to grab the value. Using that setup will avoid the deprecation, and avoid requiring us to rev the schema.

[rwjblue]

See these tests in Ember for examples of how to avoid the deprecation on create:

https://github.com/snewcomer/ember.js/blob/bb607647f107a5046a19e67042bab33ba75f6e62/packages/%40ember/-internals/runtime/tests/system/object/create_test.js#L135-L158

https://github.com/snewcomer/ember.js/blob/bb607647f107a5046a19e67042bab33ba75f6e62/packages/%40ember/-internals/runtime/tests/system/object/create_test.js#L297-L351

These techniques can be used to significantly reduce the changes required to avoid the deprecaiton.

[xg-wang]

@rwjblue oh that's nice, thanks for the examples. I'll update the PR

[rwjblue]

Moved to draft for now (lemme know when ready for another round of review)

[xg-wang]

Closed by #841