KJS: introduce new base class WebDemoExamples* tests

js/js.translator/testData/webDemoExamples1/objectOrientedHello.kt

@@ -0,0 +1,10 @@
+class Greeter(name: String) {
+    val name = name
+    fun greet() {
+        println("Hello, ${name}!");
+    }
+}
+
+fun main(args: Array<String>) {
+    Greeter(args[0]).greet()
+}