fix(a11y): Aria-hide contacts menu icon images

[ChristophWurst]

• Resolves: [BITV]: Replace entries of action menu for contacts inside of contacts menu #42708

Summary

Add aria-hidden to the decorative image icons of the contacts menu.

I do not have the means to verify the accessibility of the icon after the change. Accessibility experts, please give this a test.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[ChristophWurst]

/backport to stable28

[Antreesy]

I'm not much into the a11y details 🙈
But change looks good to me and aligned with issue discussion

[JuliaKirschenheuter]

works, thanks!

[backportbot-nextcloud]

The backport to stable28 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable28
git pull origin stable28

# Create the new backport branch
git checkout -b fix/foo-stable28

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable28

Error: Unknown error

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport

[JuliaKirschenheuter]

/backport 5198c1c to stable28

[backportbot-nextcloud]

The backport to stable28 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable28
git pull origin stable28

# Create the new backport branch
git checkout -b fix/foo-stable28

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable28

Error: Unknown error

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport