fix: handle the sorting of transformed files (#44724)

* fix: handle the sorting of transformed files

We can't use the ext property, since that is transformed, but the
history is maintained.

* test: make solutions polyVinyls for sorting

* refactor: inline prepareChallenge

* refactor: make solutions polys in getChallenges

* fix: convert each solution to a poly

* fix: skip empty solutions

* fix: get challenge file history in client

* refactor: stop calling isPoly from the client

* fix: remove debug console.log

* refactor: remove unnecessary sorting step

client/src/templates/Challenges/classic/show.tsx

@@ -547,6 +547,7 @@ export const query = graphql`
           head
           tail
           editableRegionBoundaries
+          history
         }
       }
     }

client/src/templates/Challenges/redux/index.js

@@ -2,7 +2,6 @@ import { isEmpty } from 'lodash-es';
 import { createAction, handleActions } from 'redux-actions';
 
 import { getLines } from '../../../../../utils/get-lines';
-import { createPoly } from '../../../../../utils/polyvinyl';
 import { challengeTypes } from '../../../../utils/challenge-types';
 import { completedChallengesSelector } from '../../../redux';
 import { getTargetEditor } from '../utils/getTargetEditor';
@@ -58,12 +57,11 @@ export const sagas = [
   ...createCurrentChallengeSaga(actionTypes)
 ];
 
-// TODO: can createPoly handle editable region, rather than separating it?
 export const createFiles = createAction(
   actionTypes.createFiles,
   challengeFiles =>
     challengeFiles.map(challengeFile => ({
-      ...createPoly(challengeFile),
+      ...challengeFile,
       seed: challengeFile.contents.slice(),
       editableContents: getLines(
         challengeFile.contents,