adjust Java templates to:

- use CoreConfiguration for client initialisation
- use ApiException from core library
- import core library in each service

Author: marceljk

scripts/generate-sdk/.openapi-generator-ignore-java

@@ -19,3 +19,12 @@ gradle.properties
 gradlew.bat
 gradlew
 gradle/**
+
+# ApiException from core library should be used (avoid multiple ApiException imports in case different services are used at the same time)
+**/ApiException.java
+
+# Authentication classes are not required because the KeyFlowAuth is attached as interceptor
+**/auth/**
+
+# Service Configuration is not required. It only stores a defaultApiClient
+**/Configuration.java

templates/java/ApiCallback.mustache

@@ -1,8 +1,11 @@
+{{! This template was customized to add the core ApiException class as import. }}
+{{! Original template: https://github.com/OpenAPITools/openapi-generator/blob/v7.14.0/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiCallback.mustache }}
 {{>licenseInfo}}
 
 package {{invokerPackage}};
 
 import java.io.IOException;
+import cloud.stackit.sdk.core.exception.ApiException;
 
 import java.util.Map;
 import java.util.List;