Add required message attribute for Kotlin code

Author: eugeniyk

modules/openapi-generator/src/main/resources/kotlin-spring/api.mustache

@@ -88,7 +88,7 @@ class {{classname}}Controller({{#serviceInterface}}@Autowired(required = true) v
     {{{.}}}
     {{/vendorExtensions.x-operation-extra-annotation}}
     {{#isDeprecated}}
-    @Deprecated
+    @Deprecated(message="Operation is deprecated")
     {{/isDeprecated}}
     @RequestMapping(
         method = [RequestMethod.{{httpMethod}}],

modules/openapi-generator/src/main/resources/kotlin-spring/apiInterface.mustache

@@ -103,7 +103,7 @@ interface {{classname}} {
     {{{.}}}
     {{/vendorExtensions.x-operation-extra-annotation}}
     {{#isDeprecated}}
-    @Deprecated
+    @Deprecated(message="Operation is deprecated")
     {{/isDeprecated}}
     @RequestMapping(
         method = [RequestMethod.{{httpMethod}}],

modules/openapi-generator/src/main/resources/kotlin-spring/service.mustache

@@ -30,6 +30,9 @@ interface {{classname}}Service {
     {{/externalDocs}}
      * @see {{classname}}#{{operationId}}
      */
+    {{#isDeprecated}}
+    @Deprecated(message="Operation is deprecated")
+    {{/isDeprecated}}
     {{#reactive}}{{^isArray}}suspend {{/isArray}}{{#isArray}}{{^useFlowForArrayReturnType}}suspend {{/useFlowForArrayReturnType}}{{/isArray}}{{/reactive}}fun {{operationId}}({{#allParams}}{{{paramName}}}: {{^isBodyParam}}{{>optionalDataType}}{{/isBodyParam}}{{#isBodyParam}}{{^reactive}}{{>optionalDataType}}{{/reactive}}{{#reactive}}{{^isArray}}{{>optionalDataType}}{{/isArray}}{{#isArray}}Flow<{{{baseType}}}>{{/isArray}}{{/reactive}}{{/isBodyParam}}{{^-last}}, {{/-last}}{{/allParams}}): {{>returnTypes}}
 {{/operation}}
 }

modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/spring/KotlinSpringServerCodegenTest.java

@@ -4682,7 +4682,7 @@ public void testDeprecatedAnnotationOnInterface() throws IOException {
 
         assertFileContains(
                 Paths.get(outputPath + "/src/main/kotlin/org/openapitools/api/PingApi.kt"),
-                "@Deprecated @RequestMapping("
+                "@Deprecated(message=\"Operation is deprecated\") @RequestMapping("
         );
     }
 
@@ -4703,7 +4703,7 @@ public void testDeprecatedAnnotationOnController() throws IOException {
 
         assertFileContains(
                 Paths.get(outputPath + "/src/main/kotlin/org/openapitools/api/PingApiController.kt"),
-                "@Deprecated @RequestMapping("
+                "@Deprecated(message=\"Operation is deprecated\") @RequestMapping("
         );
     }
 }