Added more functionality

.../at/tuwien/api/database/table/columns/ColumnBriefDto.java

...uwien/api/database/table/columns/concepts/ConceptDto.java

...t/tuwien/api/database/table/columns/concepts/UnitDto.java

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

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

.../src/main/java/at/tuwien/entities/semantics/Ontology.java

dbrepo-metadata-db/setup-schema.sql

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

...ces/src/main/java/at/tuwien/config/WebSecurityConfig.java

...rvices/src/main/java/at/tuwien/mapper/SemanticMapper.java

.../services/src/main/java/at/tuwien/mapper/TableMapper.java

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

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

dbrepo-ui/api/semantic.service.js

dbrepo-ui/components/dialogs/EditSemantics.vue

dbrepo-ui/pages/semantic/index.vue

dbrepo-ui/pages/semantic/ontology/index.vue