j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/rawGenerics/rawGenericMethod.kt

@@ -0,0 +1,15 @@
+package demo
+
+class TestT {
+    fun <T> getT() {
+    }
+}
+
+class U {
+    fun main() {
+        val t = TestT()
+        t.getT<String>()
+        t.getT<Int>()
+        t.getT<Any>()
+    }
+}