Hiding popunder if challenge data is incomplete (#10284)

* removing file that only contained a reference to a missing folder

* fixing typo

* using full dates to avoid moment warning in tests

* more typos

* sending an empty string to vue bootstrap tooltip (disabling it) if no challenge short name is set

website/server/controllers/api-v3/challenges.js

@@ -68,7 +68,7 @@ let api = {};
 
 /**
  * @apiDefine ChallengeSuccessExample
- * @apiSuccessExample {json} Sucessfull response with single challenge
+ * @apiSuccessExample {json} Successful response with single challenge
  {
    "data": {
      "group": {
@@ -112,7 +112,7 @@ let api = {};
 
 /**
  * @apiDefine ChallengeArrayExample
- * @apiSuccessExample {json} Sucessful response with array of challenges
+ * @apiSuccessExample {json} Successful response with array of challenges
  {
    "data": [{
      "group": {