JS: create new common directory for all generated tests, migrate several tests there

js/js.translator/testData/box/closure/closureLocalFunction.kt

@@ -0,0 +1,12 @@
+package foo
+
+fun test(): String {
+    fun f(): String = "OK"
+
+    val funLit = { f() }
+    return funLit()
+}
+
+fun box(): String {
+    return test()
+}