Gallery: Improve mobile lightbox with animated swiping

[jasmussen]

What?

Followup to #62906. Adds animation to the swiping gesture for mobile galleries:

Why?

When you have a gallery set to lightbox ("expand on click"), no mobile you can open it and use a swipe gesture to advance between images. However there is no visual feedgback that this is possible. This PR adds that.

Testing Instructions

Create a gallery, set to expand on click, then test on mobile, or using the web-inspector set to device emulation. Test swiping images to advance.

Use of AI Tools

Claude Opus 4.7.

[github-actions]

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Co-authored-by: jasmussen <joen@git.wordpress.org>

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[github-actions]

Size Change: +1.27 kB (+0.01%)

Total Size: 8.59 MB

📦 View Changed

Filename	Size	Change
build/modules/block-library/image/view.min.js	3.03 kB	+390 B (+14.75%)	⚠️
build/styles/block-library/image/style-rtl.css	3.03 kB	+118 B (+4.05%)
build/styles/block-library/image/style-rtl.min.css	1.97 kB	+104 B (+5.57%)	🔍
build/styles/block-library/image/style.css	3.05 kB	+124 B (+4.24%)
build/styles/block-library/image/style.min.css	1.97 kB	+106 B (+5.7%)	🔍
build/styles/block-library/style-rtl.css	21.8 kB	+111 B (+0.51%)
build/styles/block-library/style-rtl.min.css	18.3 kB	+105 B (+0.58%)
build/styles/block-library/style.css	21.9 kB	+113 B (+0.52%)
build/styles/block-library/style.min.css	18.2 kB	+100 B (+0.55%)

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