[Server] Read-only CORS, and query filters

[tx0c]

the GraphQL API should support CORS for read-only query from any site, to enable a 3rd party discovery portal site to be possible:

and filters:

{
  viewer {
    recommendation {
      hottest(input:{filter:{language:"ru"}}) {
        totalCount
        pageInfo { hasNextPage }
        edges {
          ... on ArticleEdge {
            node {
              id title slug summary dataHash mediaHash
            }
          }
        }
      }
    }
  }
}