Added additional query for single case

[smartcoder-7]

• What to solve
  It is very common to use storybook's knobs addon for storybook component nowadays. The screenshot results can vary depending on how to set knobs, example: background: blue or red.
  Also, they are set as query strings in browser or puppeteer. Currently, the package doesn't support to set specific knobs.
  This is very similar to this one [Feature proposal] Integrate with the knobs add-on #34
  But in short, I think we need ability to configure storybook component out of box --- from cli

• Solution
  Additional query param has been added in this commit to cli interface and StorybookPreviewBrowser to go to specific version of story. This works for knobs or args for controls in v6. But need to stick to this when writing the query to pass over to cli param (additionalQuery) . https://storybook.js.org/docs/react/writing-stories/args#setting-args-through-the-url

• Note
  It has to be used for one specific story. Otherwise, it will be appended to other stories when trying to get all the screenshots.

[Quramy]

Also, they are set as query strings in browser or puppeteer. Currently, the package doesn't support to set specific knobs.

It's cool 😄

Thanks for PR. Would you add e2e test cases ?

[smartcoder-7]

Also, they are set as query strings in browser or puppeteer. Currently, the package doesn't support to set specific knobs.

It's cool 😄

Thanks for PR. Would you add e2e test cases ?

I've added a e2e test case for v6 when using args for control. because it is using old version of storycap, I can't see the correct result but can you verify that is working fine?

[smartcoder-7]

i was able to add more e2e test case and sample for storycap.
also, verified it is working as expected using yarn e2e