Add grab cursor style for Block mover drag handle button

[kutsu123]

What?

Add grab cursor style for Block mover drag handle button

Why?

As part #50789

How?

The cursor style specification in edit mode was missing, so a new grab style specification has been added.

Testing Instructions

• Make sure you are in edit mode.
• Add two arbitrary blocks.
• Select one block and place the cursor on "drag handle".
• Make sure the cursor is set to grab.

Testing Instructions for Keyboard

Not supported as it is not within the scope of Keyborad operation

Screenshots or screencast

[github-actions]

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[t-hamano]

LGTM 👍

I believe this issue is a regression caused by the removal of cursor:glab; when the Block Mover component was cleaned up in #40379.

Thanks for your contribution!

[github-actions]

Congratulations on your first merged pull request, @kutsu123! We'd like to credit you for your contribution in the post announcing the next WordPress release, but we can't find a WordPress.org profile associated with your GitHub account. When you have a moment, visit the following URL and click "link your GitHub account" under "GitHub Username" to link your accounts:

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Kudos!