Image: Fix caption link wrapping in wide/full alignment

[himanshupathak95]

Fixes: #67206

What?

Changes the width CSS property of links within wide and full-width image block captions to prevent caption text from splitting across lines.

Why?

Currently, when a caption in a wide or full-width Image Block contains a link, the linked text appears on a separate line from the rest of the caption text. This creates an undesirable visual break in what should be continuous caption text.

This occurs due to the width: 100% CSS property being applied to links within wide/full-width image blocks, forcing them to take up the full width and create a line break.

Testing Instructions

1. Open the block editor with a block theme (e.g., Twenty Twenty-Five)
2. Insert an Image Block and add an image
3. Add a caption like "Photo Credit: Nature is Amazing Photo Collection"
4. Select "Nature is Amazing Photo Collection" and add a link
5. Test with Wide Width alignment: Caption should now appear on one line

Screenshots

[github-actions]

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Co-authored-by: himanshupathak95 <[email protected]>
Co-authored-by: Infinite-Null <[email protected]>
Co-authored-by: jartes <[email protected]>

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