To further align with the API, we return custom JSON in order to display a
`visible` field rather than `hidden` -- a `PUT` request expects `visible`, while
a `GET` request returns `hidden`.
This also allows us to rename the `jobsetinputs` field to `inputs` for the same
reason: `PUT` expects `inputs`, while `GET` returns `jobsetinputs`.
`PUT /jobsets/{project-id}/{jobset-id}` expects a JSON object `inputs` which
maps a name to a name, a type, a value, and a boolean that enables emailing
responsible parties. However, `GET /jobsets/{project-id}/{jobset-id}` responds
with an object that doesn't contain a value, but does contain a jobsetinputalts
(which is old and should be unused).
This commit aligns the two by removing the old and unused `jobsetinputalts` from
the response and replaces it with `value`.
* made all columns available via the API (except for forceeval)
* renamed flakeref to flake to unify the API with the database schema
* renamed inputs to jobsetinputs to unify the API with the database schema