story: Convert stories to tsx

[kyubisation]

We would like to convert our stories to tsx.

[DavideMininni-Fincons]

Hello guys @kyubisation @jeripeierSBB
some notes and possible blockers about this story (see: master...chore/story-convert-stories-to-tsx):

• storybook.js has very poor documentation about writing stories in Typescript using web components; in many pages in 'Write stories', 'Write docs' etc. the snippets are missing ('This snippet doesnt exist for Web Components yet. Contribute it in a PR now. In the meantime, here’s the React snippet.').
  I found this https://storybook.js.org/blog/writing-stories-in-typescript/ but it's related to frameworks.

• about story's templates: it seems I can't use the JSX syntax, because the 'sbb-button' type is not recognized (see image); I also try the import as done here https://webcomponents.dev/docs/component-story-format (Stencil bullet point) with no success.
  So I changed to string, but this way I still can't set attributes by spreading the args variable; I have to set them manually one by one, or better, I used the newly created spreadAttribute function.
  I see some downside here, e.g. the ${text ?? ''} check for the button label.

• about docs: according to this https://storybook.js.org/docs/web-components/writing-docs/docs-page#with-mdx-documentation the readme's import should works in .js|jsx|ts|tsx stories. However, in my tsx I receive an error ("TS2307: Cannot find module './readme.md' or its corresponding type declarations.").
  As briefly discussed today, I tried something like this import markdown.md for addons "Cannot find module" storybookjs/storybook#2883 (comment), with no success .
  In the end, I found this article https://medium.com/pernod-ricard-tech/integrating-stencil-with-storybook-b12f7effa54b and I checkout-ed the related repo: then, I added the stories glob pattern in the tsconfig's 'exclude' prop and added some silencer for the import line.
  It works, but I don't really like it.

Thoughts/ideas/suggestions?

[kyubisation]

Closed via #1792