Use vite storybook plugin for storybook tests

[toger5]

run via pnpm test:storybook

Content

This PR adds the vitest-storybook plugin.
This runs playwright and executes interaction tests and runs smoke tests. All this is connected to our codecov test coverage.

Motivation and context

We would like to work with a stricter separation between viewModel logic and view.
This is a step towards this:

• the view will only run storybook tests. (smoke tests that we run with all prop configuration that is of interest for us and that we will review in storybook)
• interaction tests that only check for the most basic callbacks (click here-> callback A gets called. Nothing more)

We will then have every logic that goes beyond this in the viewModel which is easier to test view unit tests.
This saves us time from dom checking (getByRole...)

Screenshots / GIFs

Tests

• Step 1
• Step 2
• Step ...

Checklist

• I have read through CONTRIBUTING.md.
• Pull request includes screenshots or videos if containing UI changes
• Tests written for new code (and old code if feasible).
• Linter and other CI checks pass.
• I have licensed the changes to Element by completing the Contributor License Agreement (CLA)