RSDChoiceInputFieldObject

example:

   // A JSON example where this is for a single choice input field that is a `decimal` base type
   // with a survey rule where the task should exit if the matching answer is `0`. This will
   // decode the choices as an array of `RSDChoiceObject<Double>` objects.
   let json = """
       {
           "identifier": "foo",
           "type": "form",
           "prompt": "Choose a number",
           "dataType": "singleChoice.decimal",
           "uiHint": "picker",
           "choices" : [{  "value" : 0,
                           "text" : "0"},
                        {  "value" : 1.2,
                           "text" : "1.2"},
                        {  "value" : 3.1425,
                           "text" : "pi",
                           "detail" : "Is the magic number" },
                        {  "text" : "None of the above",
                           "isExclusive" : true }],
           "matchingAnswer": 0
       }
       """.data(using: .utf8)! // our data in native (JSON) format

   // A multiple choice question where the choices are coded as a list of text strings. This will
   // decode the choices as an array of `RSDChoiceObject<String>` objects where `value == text`.
   let json = """
         {
         "identifier": "step3",
         "type": "form",
         "title": "Step 3",
         "dataType": "multipleChoice",
         "choices" : ["alpha", "beta", "charlie", "delta"]
         }
       """.data(using: .utf8)! // our data in native (JSON) format

   // A single choice question where each choice has an icon image representing the choice. This will
   // decode the choices as an array of `RSDChoiceObject<Int>` objects.
   let json = """
       {
       "identifier": "happiness",
       "type": "form",
       "title": "How happy are you?",
       "dataType": "singleChoice.integer",
       "choices": [{
                   "text": "delighted",
                   "detail": "Nothing could be better!",
                   "value": 1,
                   "icon": "moodScale1"
                   },
                   {
                   "text": "good",
                   "detail": "Life is good.",
                   "value": 2,
                   "icon": "moodScale2"
                   },
                   {
                   "text": "so-so",
                   "detail": "Things are okay, I guess.",
                   "value": 3,
                   "icon": "moodScale3"
                   },
                   {
                   "text": "sad",
                   "detail": "I'm feeling a bit down.",
                   "value": 4,
                   "icon": "moodScale4"
                   },
                   {
                   "text": "miserable",
                   "detail": "I cry into my pillow every night.",
                   "value": 5,
                   "icon": "moodScale5"
                   }]
       }
       """.data(using: .utf8)! // our data in native (JSON) format

   // A JSON example where this is for a single choice input field that is a `bool` base type. This will
   // decode the choices as an array of `RSDChoiceObject<Bool>` objects.
   let json = """
       {
           "identifier": "heightLimit",
           "type": "form",
           "prompt": "Are you tall?",
           "dataType": "singleChoice.boolean",
           "choices" : [{  "value" : true,
                           "text" : "Yes"},
                        {  "value" : false,
                           "text" : "No"},
                        {  "text" : "I don't know",
                           "isExclusive" : true }],
       }
       """.data(using: .utf8)! // our data in native (JSON) format