56434: docs for search-filter, search-fixed-filter and search-configuration service; search-results, filtered-search-page and search-page components

56434: Docs for all item-page-metadata-field, related-entities, item-page and metadata-values componens

Hide metadata labels without value

Conflicts:
	src/app/core/cache/models/normalized-object-factory.ts
	src/app/core/data/base-response-parsing.service.ts
	src/app/core/shared/operators.ts
	src/app/shared/object-list/item-list-element/item-list-element.component.html
	src/app/shared/shared.module.ts

Initial German Translation 

Issue #295 Dutch translation

Czech translation

Fix for authentication

Update version of Bootstrap per CVE-2018-14041