fix: stop modal appearing in steps (#43728)

* fix: stop showing completion modal on steps

* feat: submit steps with ctrl+enter

* fix: handle ctrl+enter when not focussing editor

* fix: reset tests when user types

* refactor: pass showCompletionModal as an option

Otherwise we have to write executeChallenge(true) which does not mean
what you might reasonably expect.

* fix: always executeChallenge when not on step

* fix: update frontend project show

* fix: handle missing payload

* refactor: isProjectStep -> hasEditableRegion

* refactor: more renaming

* fix: make meta.json control multifile editor use

* fix: update the challengeSchema correctly

* Update client/src/templates/Challenges/classic/editor.tsx

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* fix: remove logging

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

tools/challenge-helper-scripts/base-meta.json

@@ -1,6 +1,7 @@
 {
   "name": "",
   "isUpcomingChange": true,
+  "usesMultifileEditor": true,
   "dashedName": "",
   "order": 42,
   "time": "5 hours",