Fix unresponsive search
Fix unresponsive search

closes #6274
- any time the search content is refreshed, start with a clean array instead of performing expensive object comparisons to remove existing content

kevinansfield/Ghost-Admin,dbalders/Ghost-Admin,airycanon/Ghost-Admin,acburdine/Ghost-Admin,JohnONolan/Ghost-Admin,TryGhost/Ghost-Admin,TryGhost/Ghost-Admin,JohnONolan/Ghost-Admin,kevinansfield/Ghost-Admin,airycanon/Ghost-Admin,acburdine/Ghost-Admin,dbalders/Ghost-Admin