Board members endpoint needed for directors page in site migration activity

As defined in eclipsefdn/it/websites/eclipse.org#549 (comment 2340108), a new endpoint will be needed for the directors and inc directors page in the eclipse.org/org/foundation section that will be migrated in the near future. This endpoint will need the ability to filter by either be or us companies, which will fetch by different relations. Data will need to be fetched from the People, OrganizationContact, and PeopleRelations tables to create the results for this endpoint.

This should be able to be supported by a single endpoint such as /foundation/info/board-members/{foundation}, where foundation is either us or be. This endpoint will contain only publicly available information, so no authentication will be needed for this new endpoint.