Fix explicit KSerializer's name & generation when used in container (#20093)

* [kotlin][client] properly reference the same custom serializer name

* [kotlin][client] properly use correct type when enum in container

Author: hrach

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

@@ -111,7 +111,7 @@ import {{packageName}}.infrastructure.ITransformForStorage
      */
     {{^multiplatform}}
     {{#kotlinx_serialization}}
-    {{#serializableModel}}@KSerializable{{/serializableModel}}{{^serializableModel}}@Serializable{{#enumUnknownDefaultCase}}(with = {{classname}}Serializer::class){{/enumUnknownDefaultCase}}{{/serializableModel}}
+    {{#serializableModel}}@KSerializable{{/serializableModel}}{{^serializableModel}}@Serializable{{#enumUnknownDefaultCase}}(with = {{{nameInPascalCase}}}Serializer::class){{/enumUnknownDefaultCase}}{{/serializableModel}}
     {{/kotlinx_serialization}}
     {{#moshi}}
     @JsonClass(generateAdapter = false)
@@ -147,16 +147,16 @@ import {{packageName}}.infrastructure.ITransformForStorage
     {{#enumUnknownDefaultCase}}
 
     internal object {{nameInPascalCase}}Serializer : KSerializer<{{nameInPascalCase}}> {
-        override val descriptor = {{{dataType}}}.serializer().descriptor
+        override val descriptor = {{^isContainer}}{{dataType}}{{/isContainer}}{{#isContainer}}kotlin.String{{/isContainer}}.serializer().descriptor
 
         override fun deserialize(decoder: Decoder): {{nameInPascalCase}} {
-            val value = decoder.decodeSerializableValue({{{dataType}}}.serializer())
+            val value = decoder.decodeSerializableValue({{^isContainer}}{{dataType}}{{/isContainer}}{{#isContainer}}kotlin.String{{/isContainer}}.serializer())
             return {{nameInPascalCase}}.values().firstOrNull { it.value == value }
                 ?: {{nameInPascalCase}}.{{#allowableValues}}{{#enumVars}}{{#-last}}{{&name}}{{/-last}}{{/enumVars}}{{/allowableValues}}
         }
 
         override fun serialize(encoder: Encoder, value: {{nameInPascalCase}}) {
-            encoder.encodeSerializableValue({{{dataType}}}.serializer(), value.value)
+            encoder.encodeSerializableValue({{^isContainer}}{{dataType}}{{/isContainer}}{{#isContainer}}kotlin.String{{/isContainer}}.serializer(), value.value)
         }
     }
     {{/enumUnknownDefaultCase}}

samples/client/petstore/kotlin-json-request-string/src/main/kotlin/org/openapitools/client/models/Order.kt

@@ -68,7 +68,7 @@ data class Order (
      *
      * Values: placed,approved,delivered,unknown_default_open_api
      */
-    @Serializable(with = OrderSerializer::class)
+    @Serializable(with = StatusSerializer::class)
     enum class Status(val value: kotlin.String) {
         @SerialName(value = "placed") placed("placed"),
         @SerialName(value = "approved") approved("approved"),

samples/client/petstore/kotlin-json-request-string/src/main/kotlin/org/openapitools/client/models/Pet.kt

@@ -70,7 +70,7 @@ data class Pet (
      *
      * Values: available,pending,sold,unknown_default_open_api
      */
-    @Serializable(with = PetSerializer::class)
+    @Serializable(with = StatusSerializer::class)
     enum class Status(val value: kotlin.String) {
         @SerialName(value = "available") available("available"),
         @SerialName(value = "pending") pending("pending"),