Icu 16546 upgrade ember for admin UI (#2793)

* v4.12.2...v5.12.0

* chore: 🤖 yarn.lock changes

* chore: 🤖 ember init blueprint changes

* chore: 🤖 yarn.lock file changes

* style: 💄 run linter and formatter

✅ Closes: https://hashicorp.atlassian.net/browse/ICU-16546

ui/admin/README.md

@@ -54,9 +54,9 @@ List of available project commands.  `yarn run <command-name>`
 
 ## Running / Development
 
-* `ember serve`
-* Visit your app at [http://localhost:4200](http://localhost:4200).
-* Visit your tests at [http://localhost:4200/tests](http://localhost:4200/tests).
+- `ember serve`
+- Visit your app at [http://localhost:4200](http://localhost:4200).
+- Visit your tests at [http://localhost:4200/tests](http://localhost:4200/tests).
 
 ### Building for Production
 
@@ -102,8 +102,8 @@ Specify what it takes to deploy your app.
 
 ## Further Reading / Useful Links
 
-* [ember.js](https://emberjs.com/)
-* [ember-cli](https://cli.emberjs.com/release/)
-* Development Browser Extensions
-  * [ember inspector for chrome](https://chrome.google.com/webstore/detail/ember-inspector/bmdblncegkenkacieihfhpjfppoconhi)
-  * [ember inspector for firefox](https://addons.mozilla.org/en-US/firefox/addon/ember-inspector/)
+- [ember.js](https://emberjs.com/)
+- [ember-cli](https://cli.emberjs.com/release/)
+- Development Browser Extensions
+  - [ember inspector for chrome](https://chrome.google.com/webstore/detail/ember-inspector/bmdblncegkenkacieihfhpjfppoconhi)
+  - [ember inspector for firefox](https://addons.mozilla.org/en-US/firefox/addon/ember-inspector/)