Fix Scala sttp generator packages (#5890)

* Fix Scala sttp generator packages

* Change package to parameterised

Author: bkowalik

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaSttpClientCodegen.java

@@ -28,8 +28,6 @@
 import java.util.List;
 
 public class ScalaSttpClientCodegen extends ScalaAkkaClientCodegen implements CodegenConfig {
-    protected String mainPackage = "org.openapitools.client";
-
     public ScalaSttpClientCodegen() {
         super();
         generatorMetadata = GeneratorMetadata.newBuilder(generatorMetadata)

modules/openapi-generator/src/main/resources/scala-sttp/apiInvoker.mustache

@@ -4,7 +4,7 @@ package {{{mainPackage}}}.core
 import org.json4s._
 import sttp.client._
 import sttp.model.StatusCode
-import org.openapitools.client.api.EnumsSerializers
+import {{{apiPackage}}}.EnumsSerializers
 import sttp.client.json4s.SttpJson4sApi
 import sttp.client.monad.MonadError