[Kotlin][Client] Enum toString handling (OpenAPITools#5327)

* Added toString to enum_class script

This toString avoids using the enum var name and uses the enum's value instead. This will fix cases when enum var name and value are quite different.

* Updated enum template

Co-Authored-By: Jim Schubert <[email protected]>

Co-authored-by: Jim Schubert <[email protected]>

Author: 2 people

modules/openapi-generator/src/main/resources/kotlin-client/enum_class.mustache

@@ -41,6 +41,14 @@ import kotlinx.serialization.internal.CommonEnumSerializer
 
 {{/enumVars}}{{/allowableValues}}
 
+	/**
+	This override toString avoids using the enum var name and uses the actual api value instead.
+	In cases the var name and value are different, the client would send incorrect enums to the server.
+	**/
+	override fun toString(): String {
+        return value{{^isString}}.toString(){{/isString}}
+    }
+
 {{#multiplatform}}
     {{#nonPublicApi}}internal {{/nonPublicApi}}object Serializer : CommonEnumSerializer<{{classname}}>("{{classname}}", values(), values().map { it.value.toString() }.toTypedArray())
 {{/multiplatform}}