Refactoring: use toList for stream collection

...de/deadlocker8/budgetmaster/database/DatabaseService.java

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

...er8/budgetmaster/database/model/v6/BackupDatabase_v6.java

...locker8/budgetmaster/reports/settings/ReportSettings.java

...locker8/budgetmaster/transactions/TransactionService.java

...a/de/deadlocker8/budgetmaster/utils/types/MonthNames.java

...java/de/deadlocker8/budgetmaster/utils/types/WeekDay.java

...ntegration/EnsureAllIconizableHaveAnIconInstanceTest.java