Refactor server responses #882
Description
Right now the type of response and status code is embedded in the Response files (e.g., look for ok $ toResponse), and repeated across multiple files.
It would be nice to have a cleaner separation between the response creation, and the raw Html type which is used to actually specify the content of the response, leaving the specification of different views (e.g. Graph or Grid) completely separate from the ok $ toResponse.