OZG-7038 move xta classes to common package; combine xta service class

...in/java/de/ozgcloud/archive/common/xta/XtaFileHelper.java

...main/java/de/ozgcloud/archive/common/xta/XtaFileType.java

.../java/de/ozgcloud/archive/common/xta/XtaFileXmlUtils.java

...loud/archive/common/xta/XtaImportConfirmationHandler.java

...a/de/ozgcloud/archive/common/xta/XtaMessageScheduler.java

.../main/java/de/ozgcloud/archive/common/xta/XtaService.java

...ver/src/main/java/de/ozgcloud/archive/xta/XtaService.java

...ve/common/xta/AbgabeImportBestaetigen0402TestFactory.java

...ava/de/ozgcloud/archive/common/xta/XtaFileHelperTest.java

...va/de/ozgcloud/archive/common/xta/XtaFileTestFactory.java

...a/de/ozgcloud/archive/common/xta/XtaFileXmlUtilsTest.java

.../archive/common/xta/XtaImportConfirmationHandlerTest.java

.../ozgcloud/archive/common/xta/XtaMessageSchedulerTest.java

...de/ozgcloud/archive/common/xta/XtaMessageTestFactory.java

...t/java/de/ozgcloud/archive/common/xta/XtaServiceTest.java

...src/test/java/de/ozgcloud/archive/xta/XtaServiceTest.java