feat: add useToggleCodeBlockButton hook to code-block package

[vodkaslime]

Description
Adding hook useToggleCodeBlockButton, similar to https://github.com/udecode/plate/blob/main/packages/indent/src/hooks/useIndentButton.ts

And adding toggle code block button to playground.

Why
From playing around with playground, I found that we could only make a code block with ```, and delete it by deleting all its contents. We don't have a button toggle to really control code block on/off in toolbar, making code block a "secret recipe" feature.

Users definitely would want a intuitive button to wrap and unwrap a code block with given content. Therefore I made this PR, adding this hook + button. I believe this not only improves our playground, but also helps other plate users, since they don't need to implement this handy hook in their own code space now.

[changeset-bot]

🦋 Changeset detected

Latest commit: f6a54ff

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@udecode/plate-code-block	Minor
@udecode/plate-basic-elements	Minor
@udecode/plate	Minor
@udecode/plate-serializer-md	Minor

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Name	Status	Preview	Comments	Updated (UTC)
plate	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Feb 21, 2024 3:18pm

[vodkaslime]

@12joan @zbeyens Please take a look when you have time, thanks!

[vodkaslime]

Btw since we have another whole repo for playground template: https://github.com/udecode/plate-playground-template, how do we keep /templates/plate-playground-template of this repo in sync with that one?

[zbeyens]

@vodkaslime Thanks for the PR! We need to wait for a release before updating the templates. Could you undo these changes for this PR?

We have an auto-sync from this repo.

[vodkaslime]

@

@vodkaslime Thanks for the PR! We need to wait for a release before updating the templates. Could you undo these changes for this PR?

We have an auto-sync from this repo.

Sure removing all template changes and post only hook changes, right? Will do now