feat: react challenges (#16099)

* chore(packages): Update redux utils

* feat(Panes): Invert control of panes map creation

* feat(Modern): Add view

* feat(Panes): Decouple panes from Challenges

* fix(Challenges): Decouple challenge views from panes map

* fix(Challenge/views): PanesMap => mapStateToPanesMap

This clarifies what these functions are doing

* fix(Challenges): Add view type

* fix(Panes): Remove unneeded panes container

* feat(Panes): Invert control of pane content render

This decouples the Panes from the content they render, allowing for
greater flexibility.

* feat(Modern): Add side panel

This is common between modern and classic

* feat(seed): Array to string file content

* fix(files): Modern files should be polyvinyls

* feat(Modern): Create editors per file

* fix(seed/React): Incorrect keyfile name

* feat(Modern): Highligh jsx correctly

This adds highlighting for jsx. Unfortunately, this disables linting for
non-javascript files as jshint will only work for those

* feat(rechallenge): Add jsx ext to babel transformer

* feat(seed): Normalize challenge files head/tail/content

* refactor(rechallenge/build): Rename function

* fix(code-storage): Pull in files from localStorage

* feat(Modern/React): Add Enzyme to test runner

This enables testing of React challenges

* feat(Modern): Add submission type

* refactor(Panes): Rename panes map update action

common/app/routes/Challenges/utils.js

@@ -13,7 +13,8 @@ export const viewTypes = {
   [ challengeTypes.video ]: 'video',
   [ challengeTypes.step ]: 'step',
   [ challengeTypes.quiz ]: 'quiz',
-  backend: 'backend'
+  backend: 'backend',
+  modern: 'modern'
 };
 
 // determine the type of submit function to use for the challenge on completion
@@ -34,7 +35,8 @@ export const submitTypes = {
   [ challengeTypes.video ]: 'video',
   [ challengeTypes.step ]: 'step',
   [ challengeTypes.quiz ]: 'quiz',
-  backend: 'backend'
+  backend: 'backend',
+  modern: 'tests'
 };
 
 // determines if a line in a challenge description