[NoArg] Reorganize module structure of NoArg plugin

plugins/noarg/testData/box/sealedClassWithExistingNoargCtor.kt

@@ -0,0 +1,14 @@
+// WITH_STDLIB
+
+annotation class NoArg
+
+@NoArg
+sealed class MappedSuperClass
+
+@NoArg
+class ConcreteClass(val x: String) : MappedSuperClass()
+
+fun box(): String {
+    ConcreteClass::class.java.getConstructor().newInstance()
+    return "OK"
+}