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

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

@@ -0,0 +1,13 @@
+package foo
+
+object A {
+    val x = 23
+    val y = { x }
+    fun foo() = { x }
+}
+
+fun box(): String {
+    assertEquals(23, A.foo()())
+    assertEquals(23, A.y())
+    return "OK"
+}