`application` builder is preferred over `browser` builder. This updates all the examples I could find to use `application` builder. A couple notes of fixes that needed to happen:
1. The testing example was broken because it relied on `~` imports in CSS files, which is a Webpack-specific features. However I don't think we need those custom styles at all, so I just removed the import altogether.
2. A few tests seemed to be affected and needed to be cleaned up.
PR Close#52361
These changes include
- Remove the usage of `enableProdMode`
- Remove `test.ts`, `polyfills.ts`, `karma.conf.js` and environment files which are no longer generated by default
PR Close#47904
remove linting from the i18n angular.json example as that is no longer
present in the boilerplace angular.json (and the two should be kept in
sync)
note: the linting was removed from the boilerplate angular.json file in PR #43592
PR Close#43747
Note that because `angular.json` is a "boilerplate" file we cannot
just add comments to the one that is actually used in the application.
Instead this commit makes a copy, which is annotated with docregions.
To ensure that this file is not ignored by the example-collector, we had to
update the `.gitignore` to not ignore this file. (This also allows the file to be
easily stored tracked in git).
PR Close#43216
