j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/constructors/nestedClassNameInSuperParameters.kt

@@ -0,0 +1,11 @@
+open class Base(nested: Base.Nested) {
+
+    class Nested(p: Int) {
+        class object {
+
+            public val FIELD: Int = 0
+        }
+    }
+}
+
+class Derived : Base(Base.Nested(Base.Nested.FIELD))