Added Kotlin Vert.x client (#13594)

* Initial version of Kotlin Vert.x client

* Initial version of Kotlin Vert.x client

* Initial version of Kotlin Vert.x client

* Fix for parseDateToQueryString issue in vert.x kotlin client

* Moved common methods from api to ApiClient in kotlin vert.x client

* Fixed issue with absolute URLs

* bearer auth for oauth

* empty request headers fix

* missing import and typo

* added uri template dependency

* added api abstractions to client generator

* added full import form infrastructure

* removed fail on unknown properties to response body parsing

* fixed error response parsing

* replace vertx client name to more unique

* multiline content type

* optional responses added to template

* additional annotations for kotlin client

* Added additionalModelTypeAnnotations parameter support to AbstractKotlinCodegen

* Updated samples and documents

* Fixed issues with gson and moshi serializers with kotlin-jvm-vertx client

* Added sample configs for kotlin-jvm-vertx clients with gson, jackson and moshi

* Added samples for kotlin-jvm-vertx clients with gson, jackson and moshi

* Included kotlin-jvm-vertx samples to test build

* Updated samples

Co-authored-by: Katja Danilova <katja.danilova@protonmail.com>

samples/client/petstore/kotlin-jvm-vertx-gson/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-all.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists