[FRONTEND] Gallery modals

[yrska]

🎯 Acceptance Criteria

• When clicking on an image in the gallery, a modal should appear with a larger version of the image.
• There should be buttons that allow the user to scroll between image modals.
• Clicking outside the modal should exit the modal.
• Upon pressing escape, the user should exit the modal.
• Arrow keys should be supported to scroll between images.
• The user should not be able to scroll before the first image and past the last image (button should not appear, relevant keyboard inputs should be consumed).

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📊 Definition of Done (DoD)

• Acceptance criteria met
• Agreed tests written
• Agreed documentation in GitHub wiki
• PR reviewed

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🔗 Dependencies

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📚 Additional Context