test-js: Use prettier and format all files

Author: https://github.com/mattco98
Commit: 6d58c48c2f
Pull-request: https://github.com/SerenityOS/serenity/pull/2689
Reviewed-by: https://github.com/linusg

Libraries/LibJS/Tests/variable-undefined.js

@@ -1,19 +1,19 @@
 load("test-common.js");
 
 function foo(a) {
-    return a;
+  return a;
 }
 
 try {
-    var x = undefined;
-    assert(x === undefined);
-    assert(foo(x) === undefined);
+  var x = undefined;
+  assert(x === undefined);
+  assert(foo(x) === undefined);
 
-    var o = {};
-    o.x = x;
-    assert(o.x === undefined);
-    assert(o.x === x);
-    console.log("PASS");
+  var o = {};
+  o.x = x;
+  assert(o.x === undefined);
+  assert(o.x === x);
+  console.log("PASS");
 } catch (e) {
-    console.log("FAIL: " + e);
+  console.log("FAIL: " + e);
 }