Extend Tizen Codegen with AbstractCppCodegen class

Description

Similar to other C++ generators, we want to extend CppTizenClientCodegen with AbstractCppCodegen: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTizenClientCodegen.java#L35

openapi-generator version

Latest master

Related issues/PRs

https://github.com/OpenAPITools/openapi-generator/pull/631#issuecomment-408218688

Suggest a fix/enhancement

If anyone wants to work on this, please reply to let us know.