fix(challenges): fix #17155

i've added a test for if else statements curly braces to ensure that every condition has to have
both opening and closing curly braces.

I've also made changes that were by scissorsneedfood.

ISSUES CLOSED: #17155

challenges/02-javascript-algorithms-and-data-structures/basic-javascript.json

@@ -5066,6 +5066,12 @@
           "testString":
             "assert(code.match(/if/g).length > 1, 'You should have at least two <code>if</code> statements');"
         },
+        {
+          "text":
+            "You should have closing and opening curly braces for each condition",
+          "testString":
+            "assert(code.match(/if\\s*\\((.+)\\)\\s*\\{[\\s\\S]+\\}\\s*else if\\s*\\((.+)\\)\\s*\\{[\\s\\S]+\\}\\s*else\\s*\\{[\\s\\S]+\\s*\\}/), 'You should have closing and opening curly braces for each condition in your if else statement');"
+        },
         {
           "text": "<code>testElseIf(0)</code> should return \"Smaller than 5\"",
           "testString":