We need pagination in the wikilambdafn_search API, similarly to the way wikilambdasearch_labels API has limit and continue parameters.

Completion checklist:

• Functionality:
  • The API response can be paginated
• Engineering:
  • There are existing and passing unit/integration tests to check multiple page responses
• Documentation:
  • The API changes must be reflected in WikiLambda API help page: https://www.mediawiki.org/wiki/Extension:WikiLambda/API