Fix 'morelike' recommendation API response
Fix 'morelike' recommendation API response

Make sure to return a string.

Bug: T251587

Pchelolo/restbase,wikimedia/restbase,wikimedia/mediawiki-services-restbase,milimetric/restbase,milimetric/restbase,wikimedia/restbase,wikimedia/mediawiki-services-restbase,Pchelolo/restbase