Visual consent step

ResearchKit provides functionality to visually present the informed consent document. When an instance of ORKVisualConsentStep is included as a step of a ResearchKit task, the sections of the consent document are presented as an animated sequence of pages. Each displayed page contains the following information:

• Title: This is the section title displayed at the top of the page. The text for the title comes from the title property.

• Short Summary: A short summary of the section displayed under the section title. The text for the summary comes from the summary property.

• Learn More button: When tapped by the user, this button triggers the modal display of the section's content.

• Image: A section-relevant image, displayed above the section title.

• Animation: This is the transition animation from the image on one section to the image on the subsequent section.

The Learn More button is only displayed if there is content information assigned to the section; a non-nil value must be...