#691 - started extracting importer classes

src/main/java/de/deadlocker8/budgetmaster/charts/Chart.java

...cker8/budgetmaster/database/importer/AccountImporter.java

...ker8/budgetmaster/database/importer/CategoryImporter.java

...locker8/budgetmaster/database/importer/ChartImporter.java

...dlocker8/budgetmaster/database/importer/IconImporter.java

...locker8/budgetmaster/database/importer/ImageImporter.java

...dlocker8/budgetmaster/database/importer/ItemImporter.java

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

...e/deadlocker8/budgetmaster/services/ImportResultItem.java

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

...in/java/de/deadlocker8/budgetmaster/utils/ProvidesID.java

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

...getmaster/unit/database/importer/AccountImporterTest.java

...etmaster/unit/database/importer/CategoryImporterTest.java

...udgetmaster/unit/database/importer/ChartImporterTest.java

...budgetmaster/unit/database/importer/IconImporterTest.java

...udgetmaster/unit/database/importer/ImageImporterTest.java