fixed some deletion bugs, merge should now be complete

.../src/main/java/at/tuwien/endpoints/ContainerEndpoint.java

...ces/src/main/java/at/tuwien/service/ContainerService.java

...src/main/java/at/tuwien/entities/container/Container.java

...s/src/main/java/at/tuwien/entities/database/Database.java

...rc/main/java/at/tuwien/entities/database/table/Table.java

...src/main/java/at/tuwien/entities/database/table/View.java

...ices/src/main/java/at/tuwien/service/PostgresService.java

...ervices/src/main/java/at/tuwien/service/TableService.java