skin(elastic): show pointer cursor on clickable items in listings

[gupta-8]

Summary

Makes clickable elements (messages, folders, address book entries) use the
pointer cursor for better UX consistency.

Changes

• Added a small CSS rule in skins/elastic/styles/styles.less to apply cursor: pointer
  on clickable list items and rows.

Notes

• This is a UI-only change; no JS or PHP logic affected.
• Maintainers can recompile the Elastic LESS files as needed.

Fixes #9999