#546 - import/export database: importing template groups is optional

...e/deadlocker8/budgetmaster/database/InternalDatabase.java

...java/de/deadlocker8/budgetmaster/services/EntityType.java

...a/de/deadlocker8/budgetmaster/services/ImportService.java

...deadlocker8/budgetmaster/settings/SettingsController.java

src/main/resources/languages/base_de.properties

src/main/resources/languages/base_en.properties

...nit/database/DatabaseParser_v8_convertToInternalTest.java

...locker8/budgetmaster/unit/database/ImportServiceTest.java