[ENHANCEMENT] Align hbs templates generated by app blueprint with Prettier defaults

[jelhan]

This aligns the HBS templates generated by ember new with Prettier's defaults for Handlebars.

Today when adopting Prettier for Handlebars in a newly generated Ember application, Prettier rewrites the comments in app/templates/application.hbs:

diff --git a/app/templates/application.hbs b/app/templates/application.hbs
index 4152aaf..0b86c10 100644
--- a/app/templates/application.hbs
+++ b/app/templates/application.hbs
@@ -1,7 +1,7 @@
 {{page-title "Croodle"}}
 
-{{!-- The following component displays Ember's default welcome message. --}}
+{{! The following component displays Ember's default welcome message. }}
 <WelcomePage />
-{{!-- Feel free to remove this! --}}
+{{! Feel free to remove this! }}
 
 {{outlet}}
\ No newline at end of file

We could avoid this unneeded churn by following Prettier code formatting in blueprints directly.

[bertdeblock]

Thank you @jelhan.

[jelhan]

@bertdeblock Updated the fixtures to fix the tests.