Added embroider-safe to ember-try scenarios

[ijlee2]

Description

I followed the Addon Author Guide to understand what I could do to prepare for Embroider landing.

I wanted to add both embroider-safe and embroider-optimized scenarios, but the latter wouldn't pass in CI. There may be two explanations:

1. I was using v0.4.0 of ember-element-helper.

   Unsafe dynamic component: cannot statically analyze this expression in $TMPDIR/embroider/6871bd/components/container-query.hbs/container-query.hbs

   Updating the addon to v0.5.0 (in Updated ember-element-helper to v0.5.0 #80) fixed the error above.

2. ember-css-modules, which is used in the demo app, is not compatible with Embroider yet (Embroider compatibility salsify/ember-css-modules#140, Embroider with staticComponents: true not working with pods components salsify/ember-css-modules#160)

   Unable to resolve local class names from dummy/components/navigation-menu/index.css; does the styles file exist?

I tried changing the demo app's components folder structure from nested to flat, in case this might help Embroider understand ember-css-modules. Changing the folder structure didn't seem to have an effect.

For now, let's check just the embroider-safe scenario.

References

• RFC #507: v2 Addon Format
• README for @ember/test-setup
• Addon Author Guide
• Embroider support from ember-element-helper