Added container quota

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

.../main/java/at/tuwien/api/container/ContainerBriefDto.java

...i/src/main/java/at/tuwien/api/container/ContainerDto.java

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

...ain/java/at/tuwien/exception/ContainerQuotaException.java

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

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

...e/src/main/java/at/tuwien/endpoints/DatabaseEndpoint.java

...src/main/java/at/tuwien/handlers/ApiExceptionHandler.java

...st/java/at/tuwien/endpoints/DatabaseEndpointUnitTest.java

.../test/java/at/tuwien/service/DatabaseServiceUnitTest.java

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

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

...a-service/test/src/main/java/at/tuwien/test/BaseTest.java

dbrepo-ui/components/container/ContainerCard.vue

dbrepo-ui/components/container/ContainerList.vue

dbrepo-ui/components/database/DatabaseCreate.vue

dbrepo-ui/layouts/default.vue

dbrepo-ui/locales/en-US.json

dbrepo-ui/pages/container/index.vue