Allow setting Query Parameters to imageSnapshot configuration

[donaldpipowitch]

Work summary

@storybook/addon-storyshots-puppeteer allows us to set a storybookUrl configuration to imageSnapshot. This is documented here and can be found in the code here.

As you can see in the linked code there are query params which are appended to the storybookUrl automatically. This makes it impossible to add your own query params which is what I plan to do with #4081. (Use a different background for storyshots.)

Where to start

Start here and either

• allow setting query params to storybookUrl and append your internal params in a smarter way or
• add a new configuration field like storybookParams which are appended internally at the correct position

Acceptance criteria

It is possible to add custom query params to the imageSnapshot.

Who to contact

I don't know? :)

[igor-dv]

I have no idea how to add labels on phone, but this one is a good first issue 😝