Use prefix comparison for starts_with #4458
Description
A GraphQL query that contains a clause name_starts_with: .. gets translated to SQL as name like '...%'. On String and Bytes columns, we only index a prefix of these columns so that the index is not usable for that clause.
Query generation should be changed to generate something like left(name, 256) like '...%' if the search term is shorter than 256 characters, and to left(name, 256) = left('...', 256) and name like '...%' if the search term is longer than that.