Better handling for deleting items from the current list with autocomplete element

1. Create 3 official tags: cat, dog, chicken 2. Add a blog post and play with the tags field on this page. 3. Add these tags (don't save the form): "cat, mongoose" 4. Use the keyboard to tab to the current tags list (cat, mongoose) 5. Press up or down to select "mongoose" from the list of current tags. 6. Tab away from the list of current tabs 7. Tab back to the list of current tags, verify "mongoose" is remembered as the current item in the list. 8. Delete "mongoose" by pressing enter 9. Select cat using the up and down arrow keys 10. Delete "cat" by pressing enter 11. Verify that "cat" still shows as an autocomplete suggestion for the input field. 12. Verify that "mongoose" does not show as an autocomplete suggestion for the input field. 13. Re-add cat and mongoose as current tags 14. Delete cat and mongoose by clicking on them with the mouse 15. Verify that "cat" still shows as an autocomplete suggestion for the input field. 16. Verify that "mongoose" does not show as an autocomplete suggestion for the input field.