Typing of ClassOutput

[Peter9192]

          I think the idea of this is to have ClassOutput type be 

type ClassOutput = {
    t: number[];
    h: number[];
    theta: number[];
    dtheta: number[];
    q: number[];
    dq: number[];
    dthetav: number[];
    we: number[];
    ws: number[];
    wthetave: number[];
    wthetav: number[];
}

however it is

type ClassOutput = {
    [x: string]: number[];
}

I quickly tried to typing outputVariables with as const satisfies readonly OutputVariable[], but that broke things downstream and did not have time to fix all those.

Originally posted by @sverhoeven in #138 (comment)

[Peter9192]

Fixed in #155