Product Improvement: Floating field list on Ticket Form editor

If a ticket form has many fields, it is difficult to use the right-side field picker to arrange things on the form. Some recommendations include:

• Make the field selector on the right-side of the ticket form editor "floating" i.e. the top of the field picker is not fixed to the top of the page, but follows you as you scroll down
• Allow either "Add to top" or "Add to bottom" for fields - can only do bottom for now
• Reduce visual size of fields currently on form, to make it easier to manipulate