DS249:  display subcommunities

issue 323 comcol page logo bottom padding

Angular6 upgrade

Hide the wrapper component when there is no text content

Fixed issue where facets could not be changed when you are logged in

Conflicts:
	src/app/core/cache/builders/remote-data-build.service.ts
	src/app/core/metadata/metadata.service.ts
	src/app/core/shared/item.model.ts
	src/app/shared/loading/loading.component.ts
	yarn.lock

Issue 313: add support for paginated properties on dspace objects

Issue 311: No files item page bugfix

When the subcommunity list is empty, the subcommunity section should be hidden.

#293 Added link with the query quoted for search results if empty

If there is an error 400 or a search returns an empty result this commit will show a link with the query quoted. 
Also improved testing of search results component as the component has changed.

Hide metadata labels without value