feat: Show variable matchers in the Variables tab

[PartMan7]

PR for #122

Please let me know about any recommended changes to the approach / code!

[lifeiscontent]

@PartMan7 I like the idea of adding support for variableMatcher! One idea would be to have an integration with storybook integration tests so we can use it like apollo suggests in docs for testing. e.g. being able to call variableMatcher as a mock function and actually have storybook integration tests be able to use the variableMatcher mock, what do you think? want to give it a shot? If you don't have time, I can take a look this weekend

the code I'm referring to can be found here:

https://www.apollographql.com/docs/react/development-testing/testing/

import { MockedResponse } from "@apollo/client/testing";

const dogMock: MockedResponse<Data, Variables> = {
  request: {
    query: GET_DOG_QUERY
  },
  variableMatcher: jest.fn().mockReturnValue(true),
  result: {
    data: { dog: { id: 1, name: 'Buck', breed: 'poodle' } },
  },
};

expect(variableMatcher).toHaveBeenCalledWith(expect.objectContaining({
  name: 'Buck'
}));

[PartMan7]

I'll take a look at this, thanks!

[PartMan7]

Hi, tried looking into this, but not fully sure how I could get this to work, since functions aren't stringified while passing through The Channel^TM. I'd gotten around this by calling a .toString() on variableMatcher before forwarding; do you have any ideas around this?