Develop: Add capability to delete all cached data

As a user, I want to be able to delete all my data stored in the application.

Acceptance Criteria

Application contains a link to delete all data from the settings view
User has to click OK on a confirmation dialog to ensure they want to perform this action
System deletes all stored email, notification, settings, and other data in the local data store
User is signed out and taken back to the login page
Document any relevant content in the Programmer guide (draft thoughts of usage and importantly the "Why")
Updates SRS and STP (and other docs if necessary)
Add/Update relevant unit tests