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

js/js.translator/testData/box/enum/nativeEnum.kt

@@ -0,0 +1,19 @@
+package foo
+
+@native
+enum class JsEnum {
+    Foo,
+    Bar,
+    Baz
+}
+
+// TODO uncomment when KT-5605 will be fixed
+// fun JsEnum.extImplicit() = Foo
+
+fun box(): String {
+    assertEquals(1, JsEnum.Foo)
+    assertEquals("BAR", JsEnum.Bar)
+    assertEquals("OK", JsEnum.Baz.asDynamic().ok)
+
+    return "OK"
+}