Improve editing

[lukevanin]

Current: Fields are grouped by type. Fields are edited inline. Field type is changed by dragging to a different section.

Problem: Editing controls (edit, add, move) makes the view feel busy and crowded, which impedes usability. Dragging fields is problematic (sections may be off screen requiring scrolling while dragging which is hard to do reliably, user may not know which direction to drag a field to).

Goal: Tap on a field to show an edit screen for that field. Show a picker with field types. Customise the view to accommodate the data being edited (allow multilines for addresses, disallow multiline for phone numbers and email).