refactor: drop superorder from metas (#44422)

* refactor: create superOrder from superblock

* chore: drop superOrders from meta

* fix: return null for 'certifications'

* fix: only set superOrder if it is needed

* fix(tests): remove filter from order tests

* test: use getSuperOrder, since superOrder has gone

* test: ignore certificates

* fix: getSuperOrder throw for 'certifications'

* test: remove certificate special case

It wasn't necessary, anyway (it had never been working because I put
certificate not certification)

Co-authored-by: Nicholas Carrigan <nhcarrigan@gmail.com>

curriculum/challenges/_meta/machine-learning-with-python-projects/meta.json

@@ -5,7 +5,6 @@
   "order": 2,
   "time": "150 hours",
   "superBlock": "machine-learning-with-python",
-  "superOrder": 10,
   "challengeOrder": [
     [
       "5e46f8d6ac417301a38fb92d",