fix: applying z-index consistently to sticky elements to ensure they're on top of relatively positioned siblings (#220)
fix: applying z-index consistently to sticky elements to ensure they're on top of relatively positioned siblings (#220)

Co-authored-by: Dave Lockhart <94f3e7dc5e2fa58c3f6c6ce0b154af4bd2b48ea0@users.noreply.github.com”>
BrightspaceUI/table,Brightspace/valence-ui-table,Brightspace/valence-ui-table