j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/annotations/jetbrainsNotNullChainExpr.kt

@@ -0,0 +1,22 @@
+// !forceNotNullTypes: false
+// !specifyLocalVariableTypeByDefault: true
+package test
+
+class Foo {
+    fun execute() {
+    }
+}
+
+class Bar {
+    var fooNotNull = Foo()
+    var fooNullable: Foo? = null
+}
+
+class Test {
+    public fun test(barNotNull: Bar, barNullable: Bar?) {
+        barNotNull.fooNotNull.execute()
+        barNotNull.fooNullable!!.execute()
+        barNullable!!.fooNotNull.execute()
+        barNullable.fooNullable!!.execute()
+    }
+}