Refactor the job settings. The `autoevalLockable` boolean is now
replaced with an `evalOnSubmit` nested object:
```
evalOnSubmit: {
showButton: true,
placeholder: "Scene frame range",
},
```
This makes it possible to add a placeholder text, and later maybe some
other parameters. The `showButton: true` part always has to be there, as
the entire feature is disabled with `showButton: false`, in which case
it's better to just remove the entire `evalOnSubmit` sub-object
altogether. Still, I think it's preferred to have that `showButton:
true` in there, as it makes it more explicit what this section of the
settings is for.
This commit just contains the OpenAPI definition.