Implement unranked multi-label annotation

• Verify that schema/models are ready to deal with this
• Add unordered multi-labels to scheme config interface nacsos-web/src/components/annotations/AnnotationSchemeLabelsEditor.vue
• Add unordered multi-labels to annotator interface nacsos-web/src/components/annotations/AnnotationLabels.vue
• Add component to show multi-label resolving in nacsos-web/src/components/annotations/resolve
• Update resolve view to handle unordered multi-labels /src/views/Annotations/AnnotationConfigs/AnnotationConfigResolveView.vue
• Update integrity checks /src/nacsos_data/util/annotations/validation.py
• Update resolve utils /src/nacsos_data/util/annotations/resolve
• Extend list if other changes are required.