j2k: flatten test cases and testData directory structure

Move j2k/test/tests -> j2k/tests, j2k/test/testData -> j2k/testData

j2k/testData/fileOrElement/annotations/annotationInterface3.kt

@@ -0,0 +1,20 @@
+// ERROR: Body is not allowed for annotation class
+annotation class Anon(public val value: String) {
+
+    public enum class E {
+        A
+        B
+    }
+
+    class object {
+
+        public val field: E = E.A
+    }
+}
+
+Anon("a")
+trait I {
+    class object {
+        public val e: Anon.E = Anon.field
+    }
+}