#255 Fetching and parsing browse entries

src/app/+search-page/search-service/search.service.ts

src/app/core/browse/browse.service.spec.ts

src/app/core/browse/browse.service.ts

src/app/core/cache/builders/remote-data-build.service.ts

src/app/core/cache/response-cache.models.ts

src/app/core/core.module.ts

src/app/core/data/browse-entries-response-parsing.service.ts

src/app/core/data/browse-response-parsing.service.spec.ts

src/app/core/data/browse-response-parsing.service.ts

src/app/core/data/request.models.ts

src/app/core/shared/browse-definition.model.ts

src/app/core/shared/browse-entry.model.ts

src/app/core/shared/operators.ts

src/app/shared/empty.util.spec.ts

src/app/shared/empty.util.ts

src/app/shared/mocks/mock-remote-data-build.service.ts