Failed requests return 200 response

[dancgray]

e.g get /api/tenant/{id} where id cannot be found currently returns success: false in the response body JSON with 200 status. Status code should be 404.

Download endpoint is another example (api/output/{plugin}/publish/{id}).

This is inconsistent and not very useful, also probably not aligned with Restful API standards.

[taylortom]

This will be sorted after the rewrite 😄