Scope mockData to each story

[cernymatej]

I've noticed that when 2 stories make the same request & I define a big delay, for example, on one of the mock requests, the one that belongs to the first story to be exported is used.

export const FirstStory = {
    parameters: {
        mockData: [
            {
             ...
             delay: 0,
             }
         ]
     }
}

export const LoadingStory = {
    parameters: {
        mockData: [
            {
             ...
             delay: 99999,
             }
         ]
     }
}


// there is no delay for the LoadingStory - if rendered in the <Stories /> doc block
// (works fine when rendered on its own of course)

PS: it would also be nice to have an "infinite" delay option - so that it is easier to show the loading states of components without needing to rely on a big delay integer