[kotlin-spring] Fix cookie parameter code generation in API (#17959)

* + Cookie parameter generation fixed

* Added cookie parameter mustache template for generating cookie related code
* Adapted kotlin-spring api templates to include cookie parameters
* Added tests for evaluating cookie parameter code generation
* Added configuration sample for the new cookie use case

* - Unused fake cases removed

* Removed fake cases from openapi spec that were not related to cookie usage
* Cleaned sample files

samples/server/petstore/kotlin-springboot-request-cookie/README.md

@@ -0,0 +1,21 @@
+# openAPIPetstore
+
+This Kotlin based [Spring Boot](https://spring.io/projects/spring-boot) application has been generated using the [OpenAPI Generator](https://github.com/OpenAPITools/openapi-generator).
+
+## Getting Started
+
+This document assumes you have either maven or gradle available, either via the wrapper or otherwise. This does not come with a gradle / maven wrapper checked in.
+
+By default a [`pom.xml`](pom.xml) file will be generated. If you specified `gradleBuildFile=true` when generating this project, a `build.gradle.kts` will also be generated. Note this uses [Gradle Kotlin DSL](https://github.com/gradle/kotlin-dsl).
+
+To build the project using maven, run:
+```bash
+mvn package && java -jar target/openapi-spring-1.0.0.jar
+```
+
+To build the project using gradle, run:
+```bash
+gradle build && java -jar build/libs/openapi-spring-1.0.0.jar
+```
+
+If all builds successfully, the server should run on [http://localhost:8080/](http://localhost:8080/)