Allowing users to get labels, descriptions and statements of a search entity all in one query would reduce the need for multiple queries and and function closer to how SPARQL behaves

AC:

• When using the searchItems functionality in GraphQL, a user can get the description, aliases and statement values in addition to just labels (get everything that a user can get from a lookup)

Task breakdown notes:
Implementation:

• the node field in ItemSearchResultEdge will be changed to type Item
• in SearchItemsResolver use the ItemResolver (probably?) to fetch the whole item for each search result

Docs

• update searchItems documentation to include a sentence saying that all item fields are available in search result nodes. Also add an example for getting a sitelink of all search results.