[Port dspace-7_x] Keyboard 'tab' key navigation improved

[oscar-escire]

References

• Fixes on Dspace 7 Tab navigation is not working correctly on Safari – only 3 elements receive focus #4201
• Port of Keyboard 'tab' key navigation improved #4244 to dspace-7_x branch

Description

This PR improves tab navigation across the Dspace site, primarily targeting browsers like Safari that require explicit tags to properly detect the next focusable element.

Instructions for Reviewers

• Open DSpace on Safari desktop navigator
• Use tab to change between focusable elements
• All elements like links, inputs, buttons or checkboxes will be focusable and selectable with tab in default order

List of changes in this PR:

• Added role tag to interactive elements
• Added tabindex over interactive elements to enable focusable

Checklist

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However, reviewers may request that you complete any actions in this list if you have not done so. If you are unsure about an item in the checklist, don't hesitate to ask. We're here to help!

• My PR is created against the main branch of code (unless it is a backport or is fixing an issue specific to an older branch).
• My PR is small in size (e.g. less than 1,000 lines of code, not including comments & specs/tests), or I have provided reasons as to why that's not possible.
• My PR passes ESLint validation using npm run lint
• My PR doesn't introduce circular dependencies (verified via npm run check-circ-deps)
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[tdonohue]

👍 Thanks @oscar-escire ! This looks like an accurate backport to 7.x. Code looks good.