JS stdlib api test: various changes

- Setting -Doverwrite.output=true updates gold data
- Big packages don't get split into chunks
- Unique lines in the API are marked with /*∆*/ and diff test is removed
- Annotations on separate lines and other dump format tweaks
- Test data moved to libraries/stdlib/api/
- Minor visibility fix to Enum members

libraries/stdlib/api/js/kotlin.dom.kt

@@ -0,0 +1,17 @@
+public val org.w3c.dom.Node.isElement: kotlin.Boolean { get; }
+
+public val org.w3c.dom.Node.isText: kotlin.Boolean { get; }
+
+public fun org.w3c.dom.Element.addClass(vararg cssClasses: kotlin.String): kotlin.Boolean
+
+public fun org.w3c.dom.Element.appendElement(name: kotlin.String, init: org.w3c.dom.Element.() -> kotlin.Unit): org.w3c.dom.Element
+
+public fun org.w3c.dom.Element.appendText(text: kotlin.String): org.w3c.dom.Element
+
+public fun org.w3c.dom.Node.clear(): kotlin.Unit
+
+public fun org.w3c.dom.Document.createElement(name: kotlin.String, init: org.w3c.dom.Element.() -> kotlin.Unit): org.w3c.dom.Element
+
+public fun org.w3c.dom.Element.hasClass(cssClass: kotlin.String): kotlin.Boolean
+
+public fun org.w3c.dom.Element.removeClass(vararg cssClasses: kotlin.String): kotlin.Boolean