[Java][Jersey2] Add JsonTypeName annotation (#6551)

* Mustache template should use invokerPackage tag to generate import

* add JsonSubTypes annotation to handle scenario when OAS name has special characters

* add JsonSubTypes annotation to handle scenario when OAS name has special characters. Add unit test

* run sample scripts

* fix unit test

* run sample scripts

* add minimal openapi document to show issue with special characters and discriminators

* Add 'isClassnameSanitized' tag

* Add 'isClassnameSanitized' tag

* Add 'isClassnameSanitized' tag

* Add 'isClassnameSanitized' tag

* Add 'isClassnameSanitized' tag

* Add 'isClassnameSanitized' tag

* Add unit tests for unmarshaling of discriminators with special characters

* Add unit tests for unmarshaling of discriminators with special characters

* use JsonTypeName

Co-authored-by: Vikrant Balyan (vvb) <vvb@cisco.com>
Co-authored-by: William Cheng <wing328hk@gmail.com>

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/docs/ChildSchema.md

@@ -0,0 +1,13 @@
+
+
+# ChildSchema
+
+A schema that does not have any special character.
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**prop1** | **String** |  |  [optional]
+
+
+

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/docs/ChildSchemaAllOf.md

@@ -0,0 +1,12 @@
+
+
+# ChildSchemaAllOf
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**prop1** | **String** |  |  [optional]
+
+
+

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/docs/DefaultApi.md

@@ -0,0 +1,72 @@
+# DefaultApi
+
+All URIs are relative to *http://localhost*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**testPost**](DefaultApi.md#testPost) | **POST** /test | 
+
+
+
+## testPost
+
+> MySchemaNameCharacters testPost(mySchemaNameCharacters)
+
+
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.model.*;
+import org.openapitools.client.api.DefaultApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://localhost");
+
+        DefaultApi apiInstance = new DefaultApi(defaultClient);
+        MySchemaNameCharacters mySchemaNameCharacters = new MySchemaNameCharacters(); // MySchemaNameCharacters | 
+        try {
+            MySchemaNameCharacters result = apiInstance.testPost(mySchemaNameCharacters);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling DefaultApi#testPost");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **mySchemaNameCharacters** | [**MySchemaNameCharacters**](MySchemaNameCharacters.md)|  | [optional]
+
+### Return type
+
+[**MySchemaNameCharacters**](MySchemaNameCharacters.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: application/json
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | the response |  -  |
+

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/docs/MySchemaNameCharacters.md

@@ -0,0 +1,13 @@
+
+
+# MySchemaNameCharacters
+
+A schema name that has letters, numbers, punctuation and non-ASCII characters. The sanitization rules should make it possible to generate a language-specific classname with allowed characters in that programming language.
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**prop2** | **String** |  |  [optional]
+
+
+

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/docs/MySchemaNameCharactersAllOf.md

@@ -0,0 +1,12 @@
+
+
+# MySchemaNameCharactersAllOf
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**prop2** | **String** |  |  [optional]
+
+
+

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/docs/Parent.md

@@ -0,0 +1,12 @@
+
+
+# Parent
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**objectType** | **String** |  |  [optional]
+
+
+