Response JSON when using a message field

[phendrick]

Other than a Repeater, the layout ACF field types are being excluded from the JSON response and are causing issues with the field keys.

For example, an ACF field with a 'message' and 'text_field', is returning:
advanced": [ { "title": "demo", "fields": { "1": { "name": "a_text_field", "label": "A text field", "class": "text", "value": "text field value" } } } ]

no message is returned, and the text_field key is returned as "1"