add toggle to view all alerts

[franTarkenton]

On the list alerts view page, the page should only show alerts that are active. If the user is authenticated, an additional button should be shown allowing the authenticated user to view all the alerts, ie those that are active AND cancelled.

Acceptance Criteria

• When viewing the alert list page and not authenticated should only show active alerts
• When authenticated the alert list page should continue to show only active alerts
• Add a new button / toggle to the page that allows the user to change from viewing only the active alerts to viewing all alerts
• Include some kind of attribute / color that distinguishes cancelled alerts from active alerts

depends: #77