Fixing choice attribute form
whitespace
Cleaning up choice attribute persist logic
Adding 'expanded' and 'allowMultiple' properties to choice attributes
Fixing defaults for 'expanded' and 'allowMultiple' properties
Updating field type for 'allow blank' in attribute forms
Updating validation and form error logic for attribute add/edit
Adding new tests for choice attribute (WIP) and fixing some issues with attribute forms
Updating attribute controller tests