Improve participants and event chips

[ComputelessComputer]

• Increase the width of the participants popover to 80% to accommodate longer participant names.
• Add opacity and cursor styles to the event chip when there is no event data or the current session is the onboarding session.
• Increase the width of the event popover to 72 to better display the event details.
• Limit the maximum height of the participants list to 40vh and add a custom scrollbar for better readability.