AI-836 : fixed NPE for invisible FormFields (which prevents whole Form rendering)
AI-832 : fixed description persistence for db
AI-768 : user friendly error message : "Quantity field contains invalid value. Please enter valid double value (e.g. 1, 1.3)" => "Please enter a number. For example: 15 or 2,000 or 1.5"
 Used UIMessages to ensure that the formatting corresponds to the right locale.