Correct usage of debounce calls within event handlers

Existing Behat scenarios will confirm the search functionality being changed still works, here we can assert the debouncing now functions correctly when typing quickly: Log in as admin Navigate to Language > Language packs in site administration Quickly type a long string of characters into the Search field Confirm the Available language packs element only updates once you've finished typing Navigate to Reports from user menu Create a new report from Users report source Quickly type a long string of characters into the Search field Confirm the column list only updates once you've finished typing