Incuna-surveys

* Add missing translate
* Hide submit button until form is set

* bugfix: Remove getForm() api method and dry with api.get
* bugfix: Avoid fatal error when api promise fails but there are no errors
* Compile templates with swig.
* Add proportion / field.
* Handle blank and invalid integers.
* Set up base templates that can be extended locally so blocks can be overwritten
* Modify proportion templates for styling

* Amend percentage calculation to include value of 0
* Amend HTML structure of calculate-percentage to provide class and wrapper

* Allow null responses to survey fields.

* New feature: Calculate and display the survey completion percentage.

* Add classes to radio.html for styling
* BUGFIX: Fix serializer to cope with response data that does not match the form.