j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/class/oneStaticMethodOneNonStatic.kt

@@ -0,0 +1,11 @@
+class S {
+    fun sB(): Boolean {
+        return true
+    }
+
+    class object {
+        fun sI(): Int {
+            return 1
+        }
+    }
+}