[Kotlin-Client] Model-Suffix and Model-Prefix not working

Description

When generating code for language 'kotlin-client' the model-suffix and model-prefix parameters are not applied.

If I change the language from 'kotlin-client' to e.g. 'java' the model suffix is applied correctly.

Swagger-codegen version

• 3.0.5 (tested and not working with language: kotlin-client and kotlin-server)
• 2.4.2 (tested and not working with language: kotlin)

Swagger declaration file content or url

http://petstore.swagger.io/v2/swagger.json

Command line used for generation

swagger-codegen generate -l kotlin-client -i http://petstore.swagger.io/v2/swagger.json -Dmodels --model-name-suffix DTO

Steps to reproduce

No further steps needed for reproducing. The command from above already produces the buggy models that miss the DTO suffix.

Related issues/PRs

Suggest a fix/enhancement

Adjust model-name logic to be the same as in the java generator.

Run the reported swagger-codegen command against the Petstore Swagger document and compare kotlin-client and kotlin-server output with the Java generator. Trace the Kotlin model-name logic and compare it with the Java generator's handling of model-name-suffix and model-name-prefix. Done means generated Kotlin model names include the requested DTO suffix or prefix.