[kotlin-client][kotlin-server] feature: allow creation of kotlin data classes that implement java.io.Serializable (#3997)

* feat: allow creation of kotlin data classes that implement java.io.Serializable, by adding the config option serializableModel=(true|false)

* docs: add markdown docu for new configOption serializableModel

* fix: do not use parcelize in script

* update kotlin samples

* add the option, update the doc

samples/client/petstore/kotlin-multiplatform/src/commonMain/kotlin/org/openapitools/client/models/ApiResponse.kt

@@ -25,5 +25,7 @@ data class ApiResponse (
     @SerialName(value = "code") val code: kotlin.Int? = null,
     @SerialName(value = "type") val type: kotlin.String? = null,
     @SerialName(value = "message") val message: kotlin.String? = null
-)
+) 
+
+
 

samples/client/petstore/kotlin-multiplatform/src/commonMain/kotlin/org/openapitools/client/models/Category.kt

@@ -23,5 +23,7 @@ import kotlinx.serialization.internal.CommonEnumSerializer
 data class Category (
     @SerialName(value = "id") val id: kotlin.Long? = null,
     @SerialName(value = "name") val name: kotlin.String? = null
-)
+) 
+
+
 

samples/client/petstore/kotlin-multiplatform/src/commonMain/kotlin/org/openapitools/client/models/Order.kt

@@ -32,7 +32,9 @@ data class Order (
     /* Order Status */
     @SerialName(value = "status") val status: Order.Status? = null,
     @SerialName(value = "complete") val complete: kotlin.Boolean? = null
-)
+) 
+
+
 {
 
     /**

samples/client/petstore/kotlin-multiplatform/src/commonMain/kotlin/org/openapitools/client/models/Pet.kt

@@ -34,7 +34,9 @@ data class Pet (
     @SerialName(value = "tags") val tags: kotlin.Array<Tag>? = null,
     /* pet status in the store */
     @SerialName(value = "status") val status: Pet.Status? = null
-)
+) 
+
+
 {
 
     /**

samples/client/petstore/kotlin-multiplatform/src/commonMain/kotlin/org/openapitools/client/models/Tag.kt

@@ -23,5 +23,7 @@ import kotlinx.serialization.internal.CommonEnumSerializer
 data class Tag (
     @SerialName(value = "id") val id: kotlin.Long? = null,
     @SerialName(value = "name") val name: kotlin.String? = null
-)
+) 
+
+
 

samples/client/petstore/kotlin-multiplatform/src/commonMain/kotlin/org/openapitools/client/models/User.kt

@@ -36,5 +36,7 @@ data class User (
     @SerialName(value = "phone") val phone: kotlin.String? = null,
     /* User Status */
     @SerialName(value = "userStatus") val userStatus: kotlin.Int? = null
-)
+) 
+
+