enh(settings): Semantic user table markup

[Pytal]

• For [BITV] 9.1.3.1e/8.1 - The user table represents a grid element and should be implemented as such. (1) #36921

Summary

• Add in-house table-friendly virtual list
• Always keep user actions stickied to the right when toggling columns
• Adjust tests

No visual changes

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)

[artonge]

Are the performances still good? Bart and I got caught with some limitations when we implemented our own, like img flickering and white spaces when scrolling fast.

[JuliaKirschenheuter]

huge task 🤪

[Pytal]

Are the performances still good? Bart and I got caught with some limitations when we implemented our own, like img flickering and white spaces when scrolling fast.

Not as smooth as before but lighthouse performance score is still 20/22

Performance is about the same as before in Firefox but less smooth in Chrome