j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/switch/continueAndBreakWithLabel.kt

@@ -0,0 +1,13 @@
+fun foo() {
+    @Loop while (true) {
+        when (take()) {
+            1 -> continue
+            2 -> {
+                System.out.println("2")
+                return
+            }
+            3 -> break@Loop
+        }
+        System.out.println()
+    }
+}