Add resize to Breadcrumbs and ButtonGroup overflow stories

[r100-stack]

Changes

To help me in testing useOverflow from #2120, I thought of adding resize to the overflow stories of components that use useOverflow.

Some additional improvements:

• Initial widths try to always start the story with an overflow. Because earlier, the width was something like 50%. So, on larger screens, the story used to not overflow in the beginning.
• Added helper text suggesting resizing the container to see the overflow behavior.
• Moved the overflow container to decorators for cleaner story code.

Testing

• Manually verified that the stories still look correct.
• Changed the .test.ts files to hide the helper text and then approved the failing images.

Docs

N/A