CRDCDH-80 Implement Unsaved Changes Prompt

[amattu2]

Overview

This PR covers the implementation of an "Unsaved Changes" prompt that invokes user action when leaving the current form section with unsaved changed.

Notably, when leaving a section with unsaved changes the following options become available to the user:

• Cancel – Cancel current action, hides prompt and stops invoked navigation action
• Save – Save the current form section then navigate onward
• Discard – Discards current changes and continues navigation

Note: Any changes restored (i.e. Changing the Firstname field then restoring it back to the original value) will not count toward unsaved changes.

[amattu2]

Pending font change.

[jonkiky]

LGTM!