Storybook: Add stories for BlockCard component

[Infinite-Null]

Part of: #67165

What?

This PR will add stories for the BlockCard component in the Storybook

Screencast:

https://github.com/user-attachments/assets/bf6fc401-495a-47d2-b7aa-0ac0c014b2a5

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Co-authored-by: Infinite-Null <ankitkumarshah@git.wordpress.org>

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