Fixed mapping problem where UK and FK share columns they are inserted

.../java/at/tuwien/service/SchemaServiceIntegrationTest.java

...-service/rest-service/src/test/resources/init/weather.sql

dbrepo-metadata-db/1_setup-schema.sql

...t/tuwien/entities/database/table/columns/TableColumn.java

...n/entities/database/table/columns/TableColumnConcept.java

...wien/entities/database/table/columns/TableColumnUnit.java

...ase/table/constraints/foreignKey/ForeignKeyReference.java

...ies/database/table/constraints/primaryKey/PrimaryKey.java

...en/entities/database/table/constraints/unique/Unique.java

...tories/src/main/java/at/tuwien/mapper/MetadataMapper.java

...main/java/at/tuwien/service/impl/DatabaseServiceImpl.java