Add additional properties to the choices attribute in field class for Form objects

The ChoiceField class has an attribute choices which takes a list of 2 element tuple by default.

self.field[<field name>].choices = ([
                                                                 (option_value1, option_label1),
                                                                 (option_value2, option_label2)
                                                               ])

This blueprint describes a way to extend this to define additional properties or attributes for each choice within the choices list. These additional attributes for each choice can be any HTML global attributes defined in a dictionary. For example, to define a help text for each choice:

self.field[<field name>].choices = ([
                                                                 (option_value1, option_label1, {'title': 'help text 1'}),
                                                                 (option_value2, option_label2, {'title': 'help text 2'})
                                                               ])