Fix: Verse Block Preserves Text Formatting (italic, bold, etc.) on Paste

[dhruvikpatel18]

Closes #57624

What?

This PR fixes an issue where text formatting (italic, bold, etc.) is stripped when pasting content into the Verse block.

Why?

When pasting formatted verse (poetry) into the Verse block, whitespace is preserved but all text formatting is stripped out. This creates unnecessary work for content editors who then need to manually re-add all formatting.

The Paragraph block correctly retains text formatting on paste, and the Verse block should behave similarly since verse content (poetry, lyrics, etc.) often uses italics, bolds, and similar formatting.

Testing Instructions

1. Create a post and insert an empty Verse block
2. Find a poem that includes italics, for example: https://www.poetryfoundation.org/poems/161828/luh-friends
3. Copy the poem's text and paste it into the empty Verse block
4. Verify that the italics are preserved (before this fix, they would be removed)

Testing Instructions for Keyboard

Screenshots or screencast

Before

before_verse.mov

After

after_verse.mov

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Co-authored-by: dhruvikpatel18 <dhruvik18@git.wordpress.org>
Co-authored-by: Saoming <samuel1337@git.wordpress.org>

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[hbhalodia]

LGTM!

[Mamaduka]

This was intentionally added to fix another issue in #27781 / #27660. Let's ensure we're not introducing a regression.