[carbon-web-components]: finalize Storybook v7 update

[IgnacioBecerra]

All the stories have now been merged, but there have been some issues we need to fix before finalizing the update.

Tasks

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1. resolve circular dependencies in .mdx and *.stories.ts files sometimes prevent stories to load at first
2. remove the <Meta> from some .mdx files as it prevents loading when different stories share the same documentation file
3. removing unattached .mdx files from showing up on the sidebar as standalone docs
4. Replace Description with Markdown in all the doc files, as well as updating some other deprecated SB functions
5. Update the only missing story: Stack
6. Prepare for incoming merge with main