fix: fallback to english challenges (#45635)

* fix: fallback to english challenges

All challenges will use the english version if a translated file is not
available.  SHOW_NEW_CURRICULUM still gates what's shown in the client.

* refactor: use closures to simplify createChallenge

* refactor: remove messy destructure

* refactor: add meta via helper

* fix: fallback to [] for meta.required

* fix: repair challenge.block

* refactor: use CONST_CASE for meta + challenge dirs

* fix: catch empty superblocks immediately

* fix: clean up path.resolves

* fix: invalid syntax in JS project steps

* fix: default to english comments and relax tests

Instead of always throwing errors when a comment is not translated, the
tests now warn while SHOW_UPCOMING_CHANGES is true, so that tests will
pass while we're developing and allow translators time to work.

They still throw when SHOW_UPCOMING_CHANGES is false to catch issues
in production

* test: update createCommentMap test

* refactor: delete stale comment

* refactor: clarify validate with explanatory consts

* feat: throw if audited cert falls back to english

* fix: stop testing upcoming localized curriculum

.github/workflows/node.js-tests.yml

@@ -141,7 +141,6 @@ jobs:
       - name: Set Environment variables
         run: |
           cp sample.env .env
-          echo 'SHOW_UPCOMING_CHANGES=true' >> .env
           cat .env
 
       - name: Install Dependencies