OZG-6891 Rename ClientRuntimeException to XtaClientRuntimeException

src/main/java/de/ozgcloud/xta/client/XtaClient.java

...in/java/de/ozgcloud/xta/client/core/XtaClientService.java

...java/de/ozgcloud/xta/client/core/XtaExceptionHandler.java

...cloud/xta/client/exception/XtaClientRuntimeException.java

src/test/java/de/ozgcloud/xta/client/XtaClientTest.java

...ava/de/ozgcloud/xta/client/core/XtaClientServiceTest.java

.../de/ozgcloud/xta/client/core/XtaExceptionHandlerTest.java

...xta/client/extension/XtaServerSetupExtensionTestUtil.java

...xta/client/factory/ClientRuntimeExceptionTestFactory.java