Merge remote-tracking branch 'remotes/origin/master' into submission

# Conflicts:
#	src/app/core/cache/models/normalized-object-factory.ts
#	src/app/core/cache/response.models.ts
#	src/app/core/data/registry-metadatafields-response-parsing.service.ts
#	src/app/core/data/registry-metadataschemas-response-parsing.service.ts
#	src/app/core/data/request.models.ts
#	src/app/core/data/request.service.ts
#	src/app/core/shared/collection.model.ts
#	src/app/core/shared/dspace-object.model.ts
#	src/app/core/shared/resource-type.ts